I don't know. It's a big and somewhat irreversible decision from a pay and career perspective. I can certainly see people hesitate to make the plunge and maybe stretch things out a bit further even though they're pretty sure they're fine finacially.
I think it sort of is unless someone is a real name that lots of companies would fall over themselves to hire. For most tech workers--not limited to developers--if you decide to hang up your cleats in your late 50s or 60s, it's probably going to be difficult to change your mind a couple of years later. Part-time consulting is probably easier though. (Probably less so at the moment.)
