Some people have a really toxic attitude when talking about an obscure character (and for the most part they are ironically players of said character), being emo, spreading misinformation & generally refusing to work on improving. Granted, some characters have less tools than others, but when characters have a small playerbase, their metagame is underdevelopped, regardless.
This kind of behaviour leads to people having quite a few misconceptions on those obscure characters - I know it's the case for Kirby, and I assume other people sometimes feel the same way about their main.
I could go on a rant on why Kirby is not that straightforward, how nobody plays him at a solid enough level (except MikeKirby) and how there's a lot of improvement that needs to be done, but that would be useless since nobody cares about Kirby (and for good reason, he's never played at high level) and I'm a random so I would have nothing to back me up.
Regarding the "emo" thingy, I am by no means saying that every character is equally good and that everyone should be positive (or worse, biased) towards their character, but heck, there's absolutely no need to make it worse.
Conversely, some people need to accept that their character can have a negative MU towards X character. Like, I have no problems admiting that Kirby gets obliterated by Sonic (not auto-win, per se, but large advantage).
If I ever post a MU chart (which I SHOULDN'T cause nobody gives a **** about a random's opinion, something that a lot of people don't seem to understand, or at least that's what it used to be when tier list maker got popular), my goal would be to be as accurate as possible. Not to make Kirby look like a high tier character. Putting everyone at -1 and removing every -2 won't magically solve my character's issues, just saying.
This is especially true with low/bottom tier characters, where the players will sometimes try to put down every other "bad" character and absolutely want their character to have a +1/+2 over said "bad" character. Sometimes I wanna facepalm real hard when people talk about Kirby.
TL;DR - If you feel your character is blatantly bad and have no room to grow, then just drop him and play that genkai wo koeru guy (or any top tier, for that matter), because that's a really sad mindset. There's no need to spread misinformation & make things worse for people who want to learn, improve, and show everyone what their character is capable of.
PS : I apologize for any potential spelling/grammar/etc... mistake, English is not my language. I hope it won't make my wall of text too unpleasant to read.