I've always been a proponent of this idea but I do understand the arguments against it. I can see how it could be compared with gamey "powerups", however it always struck me as more gamey to land, tower out and jump immediately back into a new plane to roar off into battle (esp if I had a pilot wound). Time compression already occurs in AH (few RL pilots were less than 5 minutes away from major air action; and our fuel burn rate is twice the RL rate I think) so its really just a question of degree of what we're willing to accept.
What I imagine is the nail-biting tension I'd feel landing at a field under attack, trying to taxi my wounded bird to the repair hangar, and then waiting around for the mechanics to scramble over her, replacing punctured oil lines, fitting a replacement elevator, swapping out a damaged gun, etc.
What if each item repaired cost a full minute in the repair hangar, and maybe 10 perk points or so? Those would be costs to pay and tradeoffs to make, so would that restore a sense of 'earning' the kills?
I think maybe HTC's perspective is the encouragement of bold pilots and flying style over timid ones who pull out of battle at the first nick to run back to the field and get repairs, or who run away from every engagement in which they don't have a clear advantage to preserve their precious kill streak.
'course that already happens now, and repair hangars might become juicy targets at fields...
Still I like to think about this option.