Yes, it's a bad thing. You can't follow up off of anything in Brawl the same way you can in Melee. This is because you can cancel hitstun with the air dodge, which also happens to increase your survivability (when you cancel the hitstun, you also stop some of the momentum that was incurred from the knockback).
There's loads of other things wrong with the engine I could list, a large sum of them amounting to shoddy coding on the developers part due to lack of time (despite how much they kept delaying the game...) Tripping and hitstun are only a small portion of what's really wrong with Brawl and what Smash 4 needs to stay away from or address/fix.