Kirby, I think, is either right where he should be or 1-2 spots lower.
He has a few problems. He has spacing issues on the ground, low mobility, weakness to projectiles, and has a very limited moveset.
Spacing: He has mediocre spacing at best. His d-tilt and f-tilt have ok range, but they aren't great. His bair is a good spacing tool, but it is easy to run under it when it is Full Hopped and punish whatever is going to happen. It isn't like Pikachu where he has speed to combat his poor spacing, he just kinda gets wrecked for it.
Low Mobility: Kirby doesn't move fast in the air or on the ground. His movements have to be very deliberate and there isn't much room for mindgames compared to other characters. He also doesn't have many combos in actuality (F-throw uair is the only legit part of his combo at 0%, it can be SDIed out of by every character) so he is a character that relies mainly on one or two hits at a time and possibly a gimp.
Projectile weakness: Because of Kirby's low mobility he seems to get destroyed by a lot of projectiles. I know Pikachu can easily time out a Kirby because Kirby simply doesn't have an answer for it aside from shield. It is hard for Kirby to get in and he doesn't have any long range attacks to really counter-act it. It is sad indeed.
Limited Moveset: Kirby only has a few viable moves: F-smash, D-smash, Dair, Bair, U-tilt, and F-tilt. His other moves just don't cut it. However, all these moves are pretty good so it balances out in how it works. However, with the limited options Kirby has, it is very easy to predict what he is going to do, much more-so than other characters. It is also bad because it is fairly easy to punish.
Kirby does also have quite a few pros on his side, including offstage prowess, kill potential, and recovery.
Kirby has 4 or 5 mid-air jumps, along with hammer to give him an extra little horizontal boost. He will rarely get gimped and he only does when he uses his jumps carelessly and gets hit out of his up-b, sending him too far to land on the stage with an up-b. Few dare to go after a Kirby offstage because of his amazing offstage game. His dair-footstool is guaranteed on a bunch of characters and his inhale-footstool works on a bunch of people as well. Bair is also a strong move to switch the position that he was just in.
Kirby also has amazing kill potential, but this clashes with his predictability. Once at 90+% as a lightweight, it is easy to tell when Kirby is going to throw out a kill move (Mostly F-smash). When you are landing and the Kirby is walking back and forth, he is going to try to F-smash your landing. I think the kill potential and predictability balance out to a still slightly positive ending, but don't think that Kirby will always be scoring easy kills, it is definitely not the case.