My guess would be the shot execution is linked to timing, so if they get the timing right the batter will reach it. Whereas IRL you will see players often struggle to hit anything down leg/behind them. A yorker to leg stump would/should clean them up, the only real attacking shot from that position would be a Buttler-esque scoop/lap over fine leg.
Wide line is 89cm, I think. Perhaps batter crease position could be limited to always leave 89cm between the edge of the pitch (where it would be a no ball) and the 'wide' zone would still be there. Personally wouldn't allow them more than, perhaps, one foot outside off and have the wide lines move with the batter.