Yes, runways are vulnerable but they've been vulnerable for over a century now, it's not a new phenomena for the 21st century. Tactical transports are all well and good but I don't think the strategic airlifter has run out of history quite yet.
So as not to hijack this thread; I agree that it is not a new phenomena. However tactical and operational fires (rockets and missiles) now have the range to attack very deep into the opponents territory with impressive accuracy, making the likelihood of airfield interdiction more probable. I agree that strat-lift remains a critical component of military operations that will not disappear any time soon. My point is that if someone is going to look at how to retain its viability in an increasingly hazardous operational environment it might be worth considering ways to allow them to operate away from massive airfields.
Alaskan bush plane tires and landing gear for a start?