The thing Skywarp is highlighting is the wrong colours, which kids notice more than the sculpting, gimmicks or faces.
Gen1 Bumblebee was still a yellow car. The gimmick HeMan and Skelator toys were still brown and blue, respectively. Case in point, Faker is an expensive toy on the secondary market because it is hard to find due to most kids not wanting or keeping a toy that was the wrong colour. The red Bumblebee was often kept as a Cliffjumper, but if we had no Cliffjumper character, that toy wouldn't have been valued by kids for being a non-show character or wrongly coloured toy.
Kenner was criticised by fans and collectors for padding out the assortment cases with dozens of multi-coloured Batmans, instead of toys of other characters. They shelf-warmed, and rejected by people who wanted a Batman toy that was black or blue... just like we reject most weird redecos of characters that have nothing to do with comic or cartoon, but merely have a prefix to their name to sell them.
If they look good or appear to homage some other character, they might do okay, but in general it is the non-canonical redecos that shelf-warm.

The Movie Dinobots would have been chosen to be in bright colours to sell them to retailers, who have to sell them to parents. If they were screen accurate, they'd look closer to the Dinobot 5-pack, and be a wall of similar looking product, that wouldn't attract the attention of parents or impulse-buying kids.