Yep, its not about not being able to get into tank (tanks are pretty unpopular compared to marksman, elite riflemen and assaults) its about turning off hull MG AI. I'm quite sure that people who want hull MG AI off have very little expirience with random crewmen. MG AI reaction time (and accuracy, a bit) should be toned down, but unless some major changes are made to the tank crew system, "allowing crew" shouldnt be "forced".
p.s. Its very easy to take down t-34 with PTRS at the moment. Ask you mates (or change your class) to take down the tank and stop running in front of it. Its a freaking tank, not a box of bolts! Its the only thing the perfect future cyborg soldiers fear in RO2.
edit:
It would be nice if there was "required" training for tank crewmen/commander, so you'll have to learn that:
As a driver:
1. You should use incremental throttle, and keep speed at about 75% to allow gunner to aim properly.
2. Learn that reloading takes about 6 seconds, so you should start maneuvering after you your gunner makes a shot and no longer than 4-5 seconds, so the gunner will have a second to correct his aim before the reload completes, or 2 seconds or even more if you've made a sharp turn.
3. Rotate your tank so the hull mg faces the location you expect enemy infantry from, or face enemy tank if you see it and you dont have time/distance to maneuver.
As a gunner:
1. Learn how to use periscope/commander cupola (and a little test where your tank is attacked from random directions).
2. Be able to destroy enemy tank in a few shots (~15 shots for 5 tanks test).
3. A small course on killing infantry behind cover with HE shells.
As a commander:
1. Complete both gunner and driver training. OR wait 20 seconds after the start of the round (10 seconds for those who completed gunner or driver training).
As a hull machine gunner:
1. Nothing.
p.s. Actually, it would be nice if every class... ok, not every - people hate tutorials, but at least SL, commander and (maybe, optional?) engineer (and AT guy) required some training too.