I can understand the scale labels on lines like the Alternators since the car mode with opening doors and hoods get just as much attention as the robot mode since other die-cast toy manufacturers do that as well. But with the main lines, especially with vehicle modes not based or loosely based on real vehicles, I don't really see much benefit (at least to me) since scale is subjective. I do like my bots to be in scale, albeit loosely and it doesn't have to be perfect, but I'd rather have a fun figure that is out of scale to others than a perfectly scaled figure that is either not.

 

Personally I think that scale adds value when it's uniform across a line, like gunpla where there are 1:144 kits, 1:100 kits, 1:60 kits, and you know that it you stick with a particular scale the figures are going to look good together. Transformers are usually scaled in bot mode and by size classes, so if we put the alt mode scale on the box we risk getting a mess where nearly each figure has its own scale. It might even be perceived negatively because it would make even more clear that the size of the vehicles aren't coherent.

 

I'm rather opposed to the pursuit of scale in the collecting of Transforming toy collecting myself.