Did you ever stop to think why more players play better on HC genius? HC tennis is easier to pick up because movement is not crucial and you can succeed with a big serve and big forehand. Sliding on clay and moving on grass can take years to learn properly. But the REAL reason why there are more good HC players than clay/grass players nowadays is *drum roll* THERE ARE WAY MORE TOURNAMENTS!!!
HC has about 65% of the tour. If you were a coach you want your kid to learn HC first, other surfaces later because he will be doing the bulk of his tourneys on hardcourts. This is not a new situation. HC came into its own in the late 80's. In the 60's,70's most of the tour was played on grass with clay thrown into the mix. Guess what, there were a lot of great grass players in that period because of it. The only guys that didn't like it were the guys who focused solely on clay because of the stark differences at the time.
Trust me, if you favour a surface on tour via nr. of tourneys, more great players come out of that surface due to the numbers of it all. In fact I would say clay season has been the most stable of them all. Grass once ruled the tour, 3 out of 4 slams were on grass, now it has been relegated to Queens,Halle and WB. HC was a non-factor in the past and now 2 out of 4 slams are on HC, 6 out of 9 masters and 65% of the tour is on this surface.