Probably expense and lack of options - housing a single family is already expensive (and often difficult to find), two right next to each other?
Nearly impossible, and definitely prohibitively expensive in any top tier city. Zuck got a lot of pushback and significant difficulty when buying a couple of adjacent lots in Palo Alto.
For most regular foks "tier" is a budget consideration. And of course usually roots (e.g. being from an area) also plays a big role in their personal "tier" ranking of a city.
There's nature all over. You can leave somewhere that's not Seattle but still in the PNW for substantially less money.
My point here is that what matters to a given person is pretty subjective, and, personally, I'd never live in Seattle again if I could help it -- and this is from someone who grew up just 90 miles north in Bellingham. (I'd live in Bellingham again.)
The point of TFA is that you just need to be together with friends, i.e. having dinner or hanging out at each other's houses most likely. You don't need a bunch of amenities.
We seem to be doing life backward: We live alone and expend effort to gather together, as if that’s the healthy baseline
It's easier to make new friends in a top-tier city, especially if you're the kind of person who likes those amenities.
The alternative is staying in some backwater place just because one of your friends is there, and you have absolutely nothing to do there except hang out with that friend, while being constantly frustrated with all the other aspects of life in that place.
My opinion of lower tier cities is that they don’t have a lot of infrastructure (See: public transit, decent internet, etc…), lack certain kinds of development (bars, coffee shops, restaurants that accommodate diets), and they tend to lack diversity.
Nearly impossible, and definitely prohibitively expensive in any top tier city. Zuck got a lot of pushback and significant difficulty when buying a couple of adjacent lots in Palo Alto.