liking to defend is not requirement for pressing. Collective strategy is. Under a tactical pressing coach a team of Ozil's could press another team mercilessly out of possession easily
You're right, a single player's actions (be it lazy defending, or a honest misjudging of the situation) could undo a good press. However, I'd imagine that good coaches have contingencies planned for these kinds of situations. Of course, if a player is half arsed all the time, then that's insubordination in my book and he should be out of the team regardless - this has nothing to do with liking to defend or not. They just need to follow instructions
A team of Ozil's could do a lot of things, what they will do is another matter. I agree coaching is paramount, but it falls apart pretty quickly when you have a lot of insubordinate, difficult to motivate players. Or older, less mobile players like Barcelona (who granted, could try harder). Personally i think you can and should have 11 players who can and are willing to work their balls off, whatever their ability. We dont have that atm and attempts to create a high pressing team out of what we have is a tall order imo.
We should be moving in that direction.