Why You Should Give New Aatrox A Chance
I may be in the minority but I'm loving the rework.
Short list of reasons why:
Old Q: Yeah, fun for jumping over walls and stunning, but when it was down it was down, it had a long cooldown, and for those 15-20 seconds you had nearly no mobility at all. ...compare with... New E: The double-store on the dash means less periods of complete cooldown, and it still goes over walls even if shorter. This is also amazing for procing his passive (see below) combined with its own steroid. If you're only using E as a wall dash and Q setup you're doing it wrong - it is a poke tool in its own right.
New W: Gives you a new tool to save your teammates - a techier one that can set up for kills and playmaking, and one that doesn't put you in direct danger like his old Q.
New Q: Provides a lot of waveclear and healing, and also helps with timing his passive properly if you're hitting edges on minions enough.
New R: This can actually be really good if you learn to time it correctly and stay up long enough, though I agree it's easy to botch. Using it as a last resort save is the wrong way and a waste of the ult You want to pop it before a fight and let it charge and then go in strong.
...and most importantly...
New passive: Brutal against hard tanks and major jungle objectives. Indeed using and noting when this is up and timing it is absolutely the key to early laning with 
.
Now I've only been in Normals with him so far, so maybe high ELO players have valid complaints, but so far he actually feels a lot like the old one but with more utility. He's not a bad champion at all.
Things I do miss:
Old Passive: The way you could proc your old passive way early was definitely techy and nice. Old W: Skillful management of this was part of the difficulty of the old champion, new one's a bit more braindead. Old R: The teamfight burst was nice.
I just feel like a lot of the people who dislike him are missing some part of his new kit and mechanics. I got a solo kill with him at Lv3 the first time trying him, against 
no less. He has a lot of sneaky damage, and I find his new sustain to be very underrated. And I definitely think that the notion that "most of his damage is on his Q" is wrong and maybe key to why a lot of people are not doing well with him - it's just not true, and if you need his Q to provide most of his damage you're missing a lot of chances. E-empowered autos are important all game - in lane, then later in teamfights against the backline. Indeed I've been taking E first and using it for poke and sustain at level 1 and it's great.
TL:DR: Expand your mind to include all the synergies in his new kit and he's actually really fun, people!