I am not sure if I understand the concern. Price, difficulty (i.e. net hashrate), and popularity go hand and hand since this is a free market. If DRK becomes popular enough for "govthugs" to even entertain the idea of developing private ASICs then the price must be MUCH higher and thus profitable to mine (even at a 5 coin reward).
You're still thinking like a rational, decent person.
Guv is not motivated by profit. It doesn't care about the price. It sees a threat to control of it's slaves and it will spend any amount of money stolen from those slaves to eliminate the threat. It makes way more money stealing, taxing, feeing. It'll blow 50mil of everyone else's money on a rack of custom ASICs to destroy DRK just for the sake of destroying DRK. It's not about profit.
If your coin doesn't move up to ASICs, you're handing "them" The Bomb that "they" will use to destroy your coin. The only way to defend against The Bomb is to be The Bomb. If your Value/mine rate keeps ASICs down, then your coin will be nuked by a custom, private, not-concerned-with-profit-or-cost ASIC. Period.
Tell me, what part of, "A one line change in the code renders ASICs instantly useless," am I wrong about?