I'm not a fan of that move either, and never made any claims there of.
I'd really like if R.O.B. had a nice option when doing a low-airdash, actually, but I just settle with letting it end and grabbing, or wavelanding out of it. His other options are far too slow to come out before he lands, don't have an active hitbox where they can land on a grounded opponent, or are Fair and can just be CC'd or shieldgrabbed when you see him flying at you slowly. The unfortunate thing is, none of his aerials really make sense to be fast/safe to throw out close to the ground, except maybe uair if it hit in front of him on the first frame or something. Bair, dair, and nair are all far too defined by how slow they are to make into something like uair is, and only nair makes a bit of sense to be sped up from a visual aspect; at what cost I wouldn't know.
Not every character gets to have good options, but it's refreshing when a character does.