I kind of felt that way when I discovered that my fish that was supposed to be a dragonscale male was probably a plakat female. But now that I know she's a girl, I don't feel so bad about her dull coloring (except when you shine a flashlight on her, then she's absolutely gorgeous with her purples and reds). She also has the most incredible personality, so that definitely makes up for her lack of fancy coloring.
When I got my new male, I was worried that I would like him better because he's flashy and fancy, but he is seriously lacking in the personality department, so my girl is still my favorite. Don't get me wrong, he still gets excited when he sees me and swims over to say hi and get fed, but he doesn't seem quite as intelligent as her, and he's certainly not as feisty as she is.
What kind of stuff does she do? Carter is so active.
Compounded by the fact that they're Betta, somewhat smarter than "just fish," with a certain cute anthropomorphic personality which we relate to.
And then there are our expectations of the animal, both in behavior and appearance.
Is it harder for mammal owners? I've never owned one---just wild birds and reptiles.
Yes. A betta is going to pass away in X years whereas most mammal species I own will pass away in XX years. If the animal is hard to live with, that can be a really long time of "insert annoying habit here". Of course it depend on the species as well. Dogs I feel have a lot more potential to be exactly what you want them to be. They want to please, and you can capitalize on that fact. My rabbit and cat? Nope. While there is limited training I can do with both, they pretty much come the way they are going to be. Grumpy rabbit is grumpy, and needy cat is needy. And of course these animals are not limited to a few gallons of space in your home, they likely need at least a room (even if in the case of the dog they are crate trained. You can't keep them locked up in a crate all day every day).
Then there are looks. Overall I have some pretty nice looking animals. However, I am potentially getting a puppy that is the ugliest little thing I have ever seen. Quite frankly, at 6-7 months she looks like a fetal pig. She is wrinkly, you can see her spine because of the way it curves, and her tail is a curly-cue. But what can you do? Personality wise she is challenging too.
Remember that the tank your fish lives in is his or her's whole world. Ask yourself this question, and answer it honestly: would you choose to live there?