>>29544902A better question is why do people pretend to hate it, or to act like they honestly have such a problem with it?
When you get right down to it, there's nothing wrong with it in the slightest. The concept and design are interesting, in that a sea lion becomes a sea lion mermaid. Primarina itself is rather cute.
For the most part, I can understand people not being fond of cute and/or feminine designs, and likely preferring more monstrous, animal-like, or 'powerful-looking' designs, but trying to say that the design is 'bad' in any real way is rather flawed. People like cute and/or feminine designs. The concept is also rather enjoyable, as is the idea of finally having a mermaid Pokemon.
In the long run, it's fine, and it is best to learn how to accept it. This doesn't mean you have to like it, but at the same time you shouldn't be trying to say it is 'bad' when it isn't.