Simply that by replacing flight training with simulator training you are missing out on some of the best and most enjoyable flying you may ever experience.
Hacking around the circuit or heading off around the countryside with all your mates in the same bit of airspace......then exchanging tales in the bar afterwards cannot be replaced with....."you won't believe what happened to me in simulator today.....yawn!"
A valid way into a difficult industry, and good luck to all, but IMHO slightly dull.
Simulation is never as much fun as the real thing now is it?