Ppl logging off when they outnumber the enemy is not what I see, I see ppl logging off because they can't win a dogfight in either a P51D or La 7 against a bunch of FM2's or LA5's (because as soon as they engage they are outnumbered 4-1). You think you're frustrated if you can't fly a P51? Wait until you can't protect a base WITH one.
Flying high ENY planes make anyone that does so a better pilot. So have the patience to be shot down in a POS but learn the weakness and strengths of that fighter. Once you have, fly even a P40F or I16 to success (as I have done many times). Is it easier and less frustrating to pwn your enemy with a P51? Sure, but it doesn't even compare to the satisfaction (and trash talking opportunity) you have when you shoot down a P51D in a P40F or I16.