Offensive Torbjorn is just a diet offensive Symmetra. Trufax.
Only with a better turret that doesn't have some disgusting cooldown and a great ult. I find Symmetra to be far too stationary for my tastes. I've definitely seen some good ones, but I prefer engie in every situation except maybe the first point on defense to get a tele up.
As for Torb, he can be played pretty quick. Run, drop a turret, and leave it there while you go elsewhere. l-click is super solid (though it requires practicing with since it drops so fast), and r-click is gross up close. He can pseudo-heal a bit using armor packs on himself too. Just because he can pump a turret to level 2 doesn't mean he should every time he drops one. On offense, the only time I'll put a level 2 up is after we clear the team, and I have the time to get a position that will be a big thorn in the opponent's side. I use the level 1 for chip damage, distraction, and time waster. Like I said, he's basically mini-sentry engineer. You can even drop one under pressure during scramble situations. It will build itself after all.
Edit:
@SanoBaron I missed your post.
Yes, Torb can be a wall (a surprisingly easy to kill wall with a surprisingly easy to kill turret which leads me to believe that the hole up style of play you see is the wrong style of play). So can Bastion. But they are more than that too.
I covered(ish) Torb above, so let's just talk Bastion. His recon mode is good. Don't set up as turret bastion unless you've got the drop (you can also set up in mid air if you can jump from something). It is also almost as fast as a reload (can't tell if it is faster or about the same but either way it is close). People who set up Bastion in one area are just asking to die whether it is from a Tracer dash, dash ult, a Reaper who gets behind you (and they all get behind you), a Hanzo ult or split arrow, etc. His recon mode has a solid gun with solid accuracy at all ranges (using burst) and solid damage. Use it, change form when you get the flank, change back when you need to reload or move, etc. Stay super mobile.
They may be less than ideal at certain roles, but lets face it, they aren't fucking up games any worse than the swarm of shitty Genjis, the double sniper comps, the tank who switches the moment the game starts, the Tracer or Pharah who refuse to touch the objectives, etc.
