I generally reject the premise of punching up versus down; but McMansion Hell is emphatically not punching down. Anyone who can afford a $1 million 5000+ square foot house deserves very little sympathy for their bad taste.
No, see the first sentence where I say I generally reject the premise of the whole concept of punching up and down (I think there is such a thing as bad tactics). My point was, however, that if you're gonna use that framework, perhaps one percenters buying ugly houses aren't exactly a sympathetic group. Even more importantly, the OP misses the entire reason punching up and down is a thing. Being rich enough to afford a McMansion means you're pretty much guaranteed to be highly privileged. It'd be pretty silly, if you're going to talk about punching up and down, to believe that ridiculing the rich with bad taste is anything but a big ol' shoryuken. I mean, even I, someone who thinks you should treat people kindly regardless of background, roll my eyes at the thought of McMansion owners feelings being hurt because people think their houses are ugly.
You are disparaging people who are not as knowledgeable as you (elitist); they didn't design the homes, nor approve the development, nor set the zoning. Their casus belli is that they are wealthier than you, and unaware that they're buying the wrong kind of house.
Making fun of rich people for buying stupid stuff isn't punching up; it's making fun of their ignorance, regardless of whether they have more or less money than you, and can be equally applied to poor people making poor purchasing decisions.
I disagree with your assessment of elitism. If every "critique" is "elitism" then I really don't know how to respond.
That's a false equivalence. Shotgun shacks and suburban housing developments aren't trying to be something they're not. And that is why you don't find ironic commentary like this directed at them.
When you put on airs, you get cut down. Is that mean? Probably. Sometimes it's also appropriate.
It's punching down: the builders/purchasers didn't know/care how to make architecturally sophisticated dwellings, which is no reason to make fun of someone. The commentary applies equally-well to pre-fab apartments, shotgun shacks, suburban housing developments, etc. It's poorly-targeted.
It's also elitist a.f. "Look at these gauche bungalows, drawn up no doubt by someone who never heard of Falling Water, let alone ever showered"