It doesn't turn well when slow (full flaps), or roll well, also if you just disengaged from a fight and won, it's not like our K4 or D9, it is a heavy mofo and it feels like it takes ages to accelerate, also there's not much of a reward for anyone who would push/fly a P51(assuming you mean mostly D's) to its limits. 5 ENY, even your dora is 15, we make some perks when we win fights

Not that perks are really any incentive what so ever, just a thought.
Anyway that's how the 51D felt the times I've flown it. Also if someone sees a super slow pony just out of a turn fight, it's like seeing a low mossie, everyone wants the runstang/easy perks (or that's what I think

)
There are however a few good pony pilots, ran into DirtDevl earlier, he was damn good, BigR comes to mind as well. Other than that though, you're right, not too many good pony pilots.