>>40037795Combination of several things.
First is being an evolution to Linoone - obviously taking a more simple animal design then turning it into a full on anthro with references to real life people is a pretty fucking huge difference. There's nothing wrong with a design changing a lot upon evolution, Zigzagoon --> Linoone is arguably an even bigger change, but it's one that just has no sense of direction or relevance to the family as a whole and the cross theme isn't enough to justify its connection to the earlier stages. I'd also argue that Linoone is one of the worst Pokemon you could give an evolution to as its relationship with Zigzagoon is one of the most thematically rounded and completed in the series making it one of the most fitting "final" stage Pokemon. It'd be like giving Salamence an evolution after finishing the "Bagon learns to fly" story or giving Swanna en evolution despite its line being "the ugly duckling" story. Doesn't really add anything while also managing to shit on the origins.
Even excluding its previous stages though, the thing just looks bad. It's hard to take it seriously, especially with those tube legs - the thing just comes across as stupid looking and not in a fun or endearing way. And while it doesn't bother me personally, a lot of people hate when Pokemon have overt "clothing" elements to the design, of which Obstagoon has several. Cramorant's bib is a far better execution of that sort of concept.
Lastly, it feels like a character first and species second. The thing just has too much prebuilt-in personality to feel like a believable breed of monster in the same way Incineroar does or something like Cubone/Mimikyu that would make more sense as a one-off encounter/mythical. Zigzagoon and Linoone have more than enough personality as a result of their quirks, taking it further is just too much which clutters the design and removes the freedom of fantasy that makes Pokemon and its designs so special.