I take issue with your term "a government subsidy." It is our money until they get it, not all theirs and a little of it might get "given" back to us.
However, aside from that, I agree with you. I don't think tax policy should be used to control, manipulate, reward, or punish particular subgroups.
My point was simply that, if there's a change in the current regulations, the results will be economically interesting, and certainly "Unexpected!" to many of those who originally thought it was a good idea.
From a political stand point, this seems to be the federal version of “we’ll have to cut police and teachers.”
Every time there is a suggestion that spending needs to be reduced at the state/local level, the threat of cutting police and teachers is thrown out to scare people.
Now, the GOP is talking about closing loopholes to increase revenue instead of raising taxes, and someone is floating eliminating the HMD? Just a scare tactic.