DOTM SPOILERS Are the autobots in the movie, (plus skids, mudflap and Jolt) the only autobots left...? or at least, the only autobots left who have not agreed to the truce made by Megs and Sentinel? have the autobots, esp Optimus, has given up on rebuilding thier race and or Cybertron...? It seems like they have lost all hope in going back or even having a chance at ending the war....Optimus' focus seems to be a 0 tolerance on protecting Earth from "suffering the same fate as Cybertron" (as he said in ROTF). Sentinel's argument at the end about why he did what he did, how it would save cybertron, almost makes the decipticons look like they have a noble cause... imagine in a survival situation, would we level a forest to save or rebuild our village, and destroy any tree huggers who stand in our way? As much as i enjoyed the film, the only real criticism i have is that i wasn't sure who i should side with...even though my instinct tells me its the autobots, by the end i was confused by OP's (seemingly) mercy-less killings, and the (seemingly) noble cause of the Decepticons.
Jolt was really an afterthought for Chevy to advertise the Volt. A plot device. Michael Bay caved in to critics on the Twins. But if you pay attention early in the NEST bay scene they were at the end of the convoy for a few seconds. According to the comics after Sentinel killed Ironhide he killed them next. As for the question if they are the only Autobots left likely not. Remember Optimus Prime's crew went under their own power to reach Earth. Arcee, Elita-1, Chromia, Sideswipe, Jolt, Skids and Mudflap, and the Wreckers Leadfoot, Topspin, and Roadbuster arrived in the Xantium. How many Autobots have access to ships? Also the problem their Space Bridge technology was with Sentinel Prime. The Ark was built to colonize planets using the Space Bridge pillars.
It was mentioned somewhere else (either forum or novel) that the Xantium showed up between the first and second movies and brought all the new Autobots from ROTF and DOTM. But the Wreckers had to stay at the ship and and that's why we didn't see them before now.
The first movie made it seem as though the Autobots are scattered across the stars, since Cybertron is dead and unlivable.
Mearing said the second wave of Autobots. The crew of the Xantium are the ROTF Autobots and the Wreckers. The Wreckers stayed with the ship. Sam says the Autobots didn't have a way off planet. Mearing corrected him. During ROTF Ratchet said they should leave Earth, Ironhide disagreed. Ergo with the new info they already have a ship.