Hazama's 5a doesn't have the range of j.C. Or at least I don't think it does. You're right, my pressure isn't that good and I never said it was. I've seen good Hazama's get mashed out of their pressure by Bang. Hazama's attacks have huge push back which require you constantly dashing and canceling the dashes into attacks. 5a doesn't let that dash cancel to happen and an IAD j.2C crossup probably won't work too well with 5a getting in the way. D-nails are a great threat to his zoning game. It's not just "HURR DURR LEARN HOW TO BLOCK DEM NAILS". If he has to stop for even an instant while trying to zone with chains, Bang will catch up to him and Bang has lots of options against an opponent blocking the D-nails. We've seen command grab traps with those a lot. Also, it's not so easy to evade the nails while you're already in chain animation. Canceling it with A and blocking gets you in Bang pressure, with B you don't know if you'll get CH or not cause of the nails' bounce and C, again the same thing. Also note that in matchup charts, it's always considered that the best players are playing and they know how to use every tool. It's not that the Bang is just gonna waste the nails like a moron and die for it and neither is the Hazama just chaining like a madman. If the Bang uses it right, the player, even if very good with their chain canceling and chain movement, will be caught in a situation where they don't want to be as a zoner. If Hazama's 5a anti-airs Bang's attempts of jumping in, Bang's 5a's huge hitbox makes up for it.
In the end, it's just my opinion on this matchup. I'm not trying to reiterate the whole worn out argument of "lol 5a" in matchups, but I believe it's a very effective tool Bang's got in a lot of matchups.
Sorry if I'm too scrub to understand the truth about this matchup but this is how I see it. (P.S. Sorry if non of my post just now made sense. lol)