Because flat red plastic (or any "lighter" colour) is always that bit translucent that it doesn't look like paint. this means light gets reflected back at you not only from the surface, but below the surface as well. this is what makes things look plasticy abd toy-like. Ironically white plastic isn't as badly affected. this will somehat flatten out the range of tones you'll see as light relfects of the differing surfaces of the toy.
Grimlock and Streak are painted silver, which makes them look pretty indistinguishable from BTs.
Tracks, Hound, Dead End, and Smokescreen are all quite dark colours, so this sub-surface scattering doesn't affect it as much (and smokescreens sponsor decals distract from it).
I've not got Alt Swindle, so I don;t know how they've dealt with the problem on him.
and on the subject of red alternators, behold Swerve
swerve = new alternator remold?
i noticed on my hound that the plastic's all glittery, so it kinda looks a little less plasticky compared to bluestreak and Sideswipe. My grimlock's a bt though, so i dont know how the alternator grimlock is (he's painted?)
man, all these remolds with different heads
how many characters can you get from one mold? i think g1 smokescreen, silverstreak, and prowl were 1 - so just 3?