It may be self-selecting tech workers who feel excessive stress from their job, or, really are disastisfied and ready for a change.

I can confess to passing the person holding the STOP and SLOW sign at a construction site, and even saying out loud, "Now that's a job I could do."

But when the fog clears, and the paycheck lands in the bank, it's, well... nah. I'd rather put up with the stress or ennui and have the cash.