IMO, they’re not so socially undesireable as they’re hard physical work and parents/kids aren’t motivated to work that hard when an AC office awaits a liberal arts grad.

My father didn’t want me to follow grandpa and be farmer or carpenter because it was a hard life. Most hvac, plumber, electricians I’ve known were following in family footsteps because it was lucrative and they were raised in it. It’s non-trivial to break into, physically demanding and years of apprenticing before you can go your own way.

It can be done, and there are great opps for those who can stick with it for 5 years. And like all trades, your market is growing because all the old guys are getting old.

http://sfelectricaltraining.org/