It depends which continuity we're talking about. If we're talking G1, then they're machines built by aliens (alien to us at least) whose programming later advanced into cognizance. If we're talking the movies (and by which I only mean the two films), it seems that they are alien in nature and that their evolution has merely brought on a mechanical form in appearance and functionality. The rules that apply here on Earth don't necessarily have to apply everywhere else in the galaxy or universe. Carbon and water don't always have to equal life.
Sentient machines. I do not like the organic aspect much. That are things I tried to overlook when watching the movie. When Ravage got his spine torn out, I was like "WTF?", and then pretended it could just be something of his inner mainframe that just looks like a spine... just like the Terminator has (is) an Endoskeleton.
I've never been a fan of the bug-faced "scary movie monster" look. I want my bots to have mechanical detail and armor, not a robo-skeleton with car bits hanging off that can't realistically transform. That being said, I'm alright with some cases of "middle-ground" and times when said bot is part organic.
For me I like the armored machine look better. G1 yea the art was fairly primitive back then but heck the art on just all the cartoons on American TV back then was fairly primitive, just look at how some of the GI Joe and Cobra vehicles looked and they didn't have to transform just get blown up every now and then. Animated, okay the look was different but it was still that nice armored look. War for Cybertron. Lots of detailing and some different elements than what we've had before but they still have that nice armored look. Seems like they could take a few hits from ranged weapons or hold up well when the fight got all up close and personal. The movies just look like robot zombies to me with bits seeming more like the dead flesh hanging off than anything that would serve as armor. Kind of hard to relate to characters when they seem weird just for the sake of looking weird. Okay and from an evolution and societal evolution stand point the movie bots just don't work at all for me. Imagine how difficult modern human society would be if people had a random number of arms, legs bent different ways, people had a random number of eyes, even making a computer key board for people with a random number of fingers and a random placement of those fingers on the hand. Just seem like to evolve with an advanced civilization a species is going to need a fairly standardized physical frame work. Also what's an alien supposed to look like? Since we haven't encountered any life from anywhere but Earth I don't think you could say one thing is more alien than another thing. We just don't know what the rules of evolution would be somewhere else, much less what the rules of evolution would be for robots.
I like elements of both. Their bodies are 100% machine in most continuities (beast series aside) - but even then in most modern incarnations (and evens o far as retconning into G1) there's the spark - which is almost certainly not mechanical, and could even be considered the 'true' cybertronian form (and the machine body is merely an avatar). That said, the spark is again, almost certainly not organic in most of the limited times we see it. More like an energy being. I don't mind techno-organic transformers - but only if they're limited. I grew tired of Beast wars continuity when transmetals mixed everything up, and then grew sick of beast machines for the same sort of reason. As for the movies, I don't think they're organic at all. What people seem to be confusing is 'organic' and 'natural' - in the movies case, the aliens are clearly mechanical. However, the way they move, and carry themselves gives a more natural vibe to their appearance, less like the traditional robot image, and more related to living creatures (of which the only reference we have is organics). Just my 2 penneth.
They seemed sort of like the same weird idea from Van Helsing. If it didn't work there I'm not sure why they would use the same bad idea for Transformers unless they were attempting some way to say they look mechanical but are organic.
The robots in ROTF especially seemed "juicier" in a way that suggests an organic life form, even if it's lubricant/coolant/fuel/whatever. It seemed they were pushing them hard as true organisms, albeit of a more mechanical nature. In general, I tend to prefer the more solid/chunky style of TF robots, but I appreciate each major 'style' of Transformers as its own entity, and don't really see one as fundamentally better than another.
I think it's funny how the fans that don't like the mechanical detail of the movie designs associate it with being something like "zombies" and "dead flesh". Meaning they are the ones who actually look at the transformers as organics in general, more then the fans who look at them as robots. I think that's just a completely and utterly superficial and shallow mentality. I'm sorry, but I can never agree with this mind set. Not just with robots but just in general character design. Characters don't have to look physically familiar in order to be relatable characters. It's all in the personality. Which I will admit, the movies do lack. But that's my point. The problem with the TF films is not in the visuals, but in the directing and writing. To say these character design don't work because they look weird, just doesn't hold up. Case in point being TFA Lugnut. Very weird looking character. But one that has amassed quite a fan base because of his character. Maybe Cybertronians are just more diverse as a "species"
I think if you are going to skip on the character then you have to go with what is familiar. Without lines you need something like facial expressions you can read or a body type that will let you read the body language of the character. Since the films aren't big on character then they need to be using all the cheats they can pull out of the bag of tricks. Now if you've got a project where there is time to actually establish characters then the need for facial expressions or body language isn't as great. Thanks to the voice acting and dialog he's given Lugnut doesn't need to facially express like a character with only a few lines. Waspinator is the same way, unusual look but thanks to the time put into the building the character you can relate to his personality instead. Even outside of Transformers WALL-E can pull off something that isn't as human because there is more than enough time in the film to latch on to his personality and exaggerated expressions. In a cartoon series or a well written comic book the look could work because you've got the element of time on your side. In a movie where it cost so much to use the characters you don't have that advantage. Thus Prime and Bumblebee have a rather human look because people need to relate to them, the Decepticons just being something to kill end up with the wilder looks because they figure no will bother to relate to the things just there to get killed.
