[atq2119]

This is an interesting question, so here's a bit of speculation.

Banter is a matter of wit. You could call it an intellectual pursuit.

Blue collar jobs are primarily not intellectual pursuits. They need their own kind of smarts, but these smarts are relatively orthogonal to the kind of linguistic smarts used in banter, and most importantly the work output itself is not intellectual. There's little chance of the banter directly getting into the work output, and so there's little direct motivation for bosses to police it.

Software development is basically entirely an intellectual pursuit that very much overlaps the wit of banter, and banter is likely to leak into the work output. Hence easter eggs are a thing. So, bosses are more likely to want to police banter-adjacent activities, which has a likely chilling effect on banter itself.

Another, more recent, factor is that more software development activity is online/remote and therefore lower bandwidth. The subtleties of banter don't convey as well as they would in-person.