>>38037247As someone who likes them, Unno tried to fit too many different themes into the design at once and while he did succeed in that goal it caused a rare case of genuine overdesign in Pokemon. None of the qualities of the designs stand out because they're all competing with each other at once.
It also doesn't help that they were an early forced gift. You just get them and it feels like they exist solely to beat the gym leader. Would have been so much better if you had to beat the monkey that's strong against you without your own and be like "Wow, what a strong pokemon. I'm so impressed I want one of my own, and there's three to pick from!"