I don't think BC4629 is trolling, but he's obviously talking about a much different/lower level of play than the rest of us are used to.
Just because people don't use a move, doesn't mean it isn't useful. Kirby's copy ability is a very unique move, since there's always another option that will do more damage. However, it focuses on a different form of long-term than other moves do.
vs. Luigi: His fireballs are probably the worst projectiles in the game, but they're still FAR from useless, and add to Kirby's approach (which he's not exactly top-tier in).
vs. Mario: These fireballs basically give a multiplier effect to the easiness of Kirby's aerial approach. Besides, they rack of damage fast.
vs. DK: Up-tilt combos into charged punch ridiculously easily.
vs. Link: Kirby boomerang is so much fun and so sick. Significantly dds to approach AND combo ability.
vs. Samus: Not nearly as useful as DK's, since Samus is really floaty and harder to combo with, but still useful.
vs. Doug: Pretty difficult to combo into a PAUNCH, but oh-so-satisfying when it happens.
vs. Ness: lol
vs. Yoshi: more lol
vs. Kirby: CANNIBAL
vs. Fox: TRIPLE SHORT HOP LAZORS WTFHAX
vs. Pikachu: Actually marginally useful for approach. I'd pass though.
vs. Jiggly: Haven't really tried it out, but Jiggly's best edgeguard game is on the ground, so I guess the recovery aspect can be useful. It might have some interesting combo implications though.
Oooh this just gave me a combo idea. I'm going to post it in the social thread.