As an instructor, teaching people who had a lot of time on flight sim computer games was a complete pain in the ass ... the more they've flown Microsoft the more useless they are in a real aircraft when studying for their PPL, because they are completely incapable of setting a visual attitude or maintaining a lookout ... they just fixate on the AH and instruments. Which arent all that great in a training aircraft of course and the aircraft just constantly woffles around the sky in a perpetual light pitch-up-pitch-down motion. And they just cannot grasp the concept of looking up and towards the end of the runway to flare the thing on landing. And, of course they reckon they know more than you because they've got 10,000 hours logged on Microsoft and you're only a poxy instructor with 1000 actual flying time in lighties, so they don't listen and pretend to humour you when you're trying to teach them the basic importance of setting a visual attitude.
I would say that excessive time on the computer when it's not being accompanied by actual time in the aircraft, is overall detrimental to a person's progress as a pilot.