If buying an house was free, you can be sure I would definitely tell that to every fucking anyone.

Guy wanted to vent about smart thermostats, explicitly said he doesn't need advice and got bajillion responses with advice, mostly from FOSS folks who couldn't contain themselves. I'd be annoyed too.

Better comparison would've been something like "Annoyed with your landlord? Go build a cabin in the woods!". Like, that's straight-up appealing to some people, but it's also not just something anyone and everyone can do.

is exactly like saying “why don’t you just buy a house?” to someone complaining about their landlord.

What an idiotic comparison.

Buying a house costs so much money and time that most people cannot afford to, and those who can generally must go into debt for most of their remaining lives in order to do so. Suggesting FOSS to replace "whatever commercial software they use" is the polar opposite, in that it's literally free (usually in both senses of the word). It's more like suggesting that someone consider a new route to commute from home to work.

Also, this opening...

Okay, all you open source evangelist people: your knee-jerk reaction to come at people

...is incredibly reductive and combative. The world needs less of that, not more.

Who is this and why should we care about his opinion?