I agree that that's part of it. While I do appreciate the close to normal transformation, it's a steep tradeoff.
But then the gimmick kind of hit diminishing returns for other reasons too. I think it's at its best when it's ad hoc, Cybertronian altmodes (Sixgun, who's mostly held back by his guns being weird cones) or ones that can wad up into modes that have a coherent shape (the Modulators, Slammer). The Junkions were harder to make work because as armor bits they were more obviously 1/4 a car, a bike wheel, etc. I think the Modulators lent themselves best to it, and maybe the Fossilizers (although that was also hit or miss). Part of the problem is that probably for safety reasons, some parts had to always be riveted together, so you'd always be wielding someone's waist and hip stumps. And "wear chunk of thing as platform boots" can only be done so many times.
The Armorizers idk if I even really want to count since it was basically pop off a lower arm or a shin plate, whatever. They seemed to do the least. Although they had more than that undermining them; the bike mold will always look silly, all jagged rock on three perfectly clean and round bike tyres with spokes and everything.
I did appreciate more conventional non-partsforming transformations, but an exception could've been made for Amalgamous. That dude has every reason to basically be Modulok but with gun and vehicle bits (so more than Multi-bot).
