I buy figures because I like the character.

It's less about the toy. If the toy is rubbish, then I'll happily leave it sealed.

Sadly, I like a lot of unrepresented characters, disliking a lot of the popular ones. That said, I don't think I dislike any character enough to negatively impact my enjoyment of a figure, I just wouldn't buy more than the one or two figures I'd need to represent that character.

And man o man am I sick of Optimus Prime.

Some company gets the license for Transformers, they make a Prime, I buy it to support the line, they stop making their product.... rinse, repeat and my collection starts to look more like an Optimus Prime collection and less of a Transformers collection.