First of all, I never said his air-speed should be nerfed.
Secondly, Chrom does have Defensive options off-stage.
-All his Aerials
-A Counter
-Recovering high with Up-B
-Air-dodging to the ledge
That's about the same coverage or more then these characters:
Chrom ain't helpless off-stage, he's got more breathing room to work with at his point of disadvantage.
Edge-guarding is a risk, I know.
But if you're in a last stock case, Chrom's off-stage and at 100%, you're at 23%, you've worked hard to get Chrom off-stage and you want to get Chrom at his weakest. You know his ledge options are good enough for him to reset neutral (or even press him in advantage) off of one guess or mistake on your end.
You wait for him to come to you because you know he can swing at you and cover himself.
Your character doesn't have any "easy ways" of killing him, so you have to challenge him.
Chrom is approaching the ledge. Chrom up-b's to the ledge, you go out to the ledge to seal the stock, your move doesn't hit him, you ended getting caught in his Up-B and dying first (assuming the Chrom didn't even stap to the ledge), losing the game because you got "greedy" and trying pressing your advantage state.
What will that teach you and the Chrom.
-That you shouldn't go off-stage and edge-guard?
-That Chrom can just get away with winning by his simple up-b recovery
-That you shouldn't press advantage when you have the chance
If you're Chrom and you get launched off-stage, you shouldn't just get a free pass because you caught your opponent in Up-B at the right time.
You were off-stage, you have played better on stage since you have the tools, you are at risk, you should work to get out of it by doing more then just pressing Up-B when you're both at a last stock situation...
I haven't even talked about if the positions were reversed.
Chrom can just edge-guard by Up-Bing against your recovery and take an easy win off just that.
On a character who's already pretty dominate and rewarding on-stage.
If other, weaker characters like Ganon can't have this game-winning, clutch option, then why should Chrom...
Anyway, that's my argument.
Edit: I would be mildly okay with them just nerfing some other strong options to off-set the Chromcide.
I'd just prefer to remove the silly game-change nonsense first.