Yeah its a stupid argument really. It like saying 'no point in getting an expensive PC when i can buy a much cheaper Xbox and play the same multipl;atform games and Xbox games.What the grown ups here are saying is that not all of us want to play Microsofts games on a PC.
If I had a buck for everyone that didn't understand people don't want to play on PC...
Fact is there will always be PC only players, Console only players, and PC and Console players. Microsoft now cater to all those.