[ZeoRangerV]

Because mainly it creates a distinct visual difference between them and the Autobots. But its not like its constantly happened since the movies so I don't really understand your point there. Neither Animated or Prime had Decepticons with animal traits save for the ones that were actually animals (and Airachnid).

I don't particularly like a lot of them either, but then I have issues with the 'Cons in RID because half of them aren't really 'Cons at all, they're just petty criminals that seem to have gotten branded as them.

RID as a show has grown on me a lot since it started though.