Taking this in reverse order:
I think the answer has to do with our beginnings as a puritanical society, along with the "gospel of prosperity." There is a social taboo against being poor in America. We assume that the poor must be at fault for their condition, because they would be rich if they were pious. Likewise, we assume that the rich are successful due to their virtue, even if their wealth depends on the economic infrastructure maintained by all of our taxes.
Anyone who claims that poverty is largely down to choice is just as much of a fool as anyone who claims that wealth is largely a matter of luck. Some folks are poor because they made bad choices, some folks are rich because they were in the "lucky sperm club". But not all. No question that the playing field is far from level.
Which is why we transfer (not "steal") assets from one group to the other to provide
necessities including education (and, in civilised countries, health care).
On the flip side, most median income or better folks are there because they are exchanging hours of their lives for money. Which makes taking their assets an evil that can only be justified by avoiding a greater evil (i.e. providing essential services). Assuming you're happy with the labour theory of value, of course.
So, yes, people have money because of the common economic infrastructure, but also because of their own hard work.
Nobody's answered my question: Should people who take the homeowner's deduction on their income tax return, be required to take a drug test and to perform community service?
They are definitely at fault for buying a house without having enough money to pay cash for one.
Well, they borrow the money, and receive some degree of subsidy due to government involvement in the mortgage market (hmm, best not go there.... ;-) )
I suppose there isn't a single objective "answer" to your question, just a number of different points of view. I'd describe myself as loosely "socialist about needs, libertarian about wants", which ends up as saying "only net producers get luxuries" In that framework, most - but not all - folks who are taking a mortgage interest deduction are putting in more than they take out. So they're entitled to 100% of any surplus to spend on luxuries.
(Now, the question of whether we're actually meeting all needs is a whole other topic, but it doesn't change the basic argument).
Other points of view may see things differently. If you believe in concepts like "relative poverty" then what I've said will make little sense.