For me it isn't much intolerance, it's more of a lack of patience for the careerists.

Working with people that love what they're doing can be very chill. Working with people angling for a promotion, taking shortcuts, one-upping the co-workers and still not pulling their weight is exhausting.

This is not a new phenomenon, in the past this kind of dev also existed. Lots of people studied CompSci but didn't want to be a "lowly developer" for long and were just making time to "become a manager". Of course they never put the work for that as well. Today it's half of the people I interview: they never got good enough to become a manager, and never become good enough to pass most interviews in the market of today.

On the other hand, I got a couple manager friends who love coding and are trying to become individual contributors, but keep getting pulled into leading projects because of their expertise.

Don't get me wrong, though, everyone wants to make money and have a good career, I just prefer working with a different kind of person.