All in all, ATs are going to exist in smash. If not melee ATs or brawl ATs, then you're going to have smash 4 ATs. There's going to be millions of people playing this game, so something's going to be found out in 1-2 months. It'd be crazy for someone to find out something advantageous and not use it.
In street fighter games, you've had tech blocking, CC valle, roll grabs (-cross snk) and the focus attacking cancels. And each of these techniques have been staples of the games. To the point, if I talk to someone about getting in a casual game with them , off rip they'll feel like I will play using the ATs.
For all the people complaining about them not getting melee techniques down and losing in tournaments, melee has been out for a long time to the point it's the street fighter 3rd strike of the smash world where it's the epitome of what amazing smash is supposed to be. This why sakurai made a completely different game with its own mechanics and ATs to be discovered, and this was the same thing Ono did with street fighter, yet each of those games has their own ATs.
Even outside of fighting games there's ATs, in War (technological advancements), chess (grandmaster strategies and gambits), Magic the gathering (Expensive cards that have amazing amounts of synergy), Mario go kart 8 (fire hopping).
If you don't like it, then you can leave the community. I didn't like how I had to be learn infinites to stand a chance in MvC3 , so I left. I didn't like how sfxt was the same way so I left. I didn't like how I have to have a deck worth $600 and above to have fun in mtg , so I left. If I sat around complaining and being disgruntled about the higher level of things whether it was ATs , cards, or chess moves, I'd be wasting my time and others time reading it when we both could put our time to better uses.
For the people complaining about not having enough time to learn, I've taken full college classes, worked full time, partied with my friends drinking and popping molly, but in 10 small mins of everyday I'd practiced my srk -> fadc -Ult 1 to the point I can be sloshed and still pull it off. Please come with a legit reason for them not being in the game rather than being lazy.
To the OP: I feel ATs of some kind should be in the game and reward the player for finding them. Even if they're character specific then it expands the game. When I got into Brawl and I found out how deep things go with Wario then it made me stay because it gave the game Depth.