> As a professor, I believe virtually all profs should have industry experience and occasionally go back for a year or two. (I’ve bounced back and forth!)

For quite some professors I imagine that going back to industry would make them a lot more arrogant. In academia, being surrounded by very smart people dampens the arrogance a lot because you realize that you may be smart, but not that smart. On the other hand, in industry you have much less people around you that can intellectually stand up against you, which easily makes you smug.

It depends on the industry. In high tech they would not carry the "professor" shine, they are just one more person in the meeting.

They would also quickly suffer from corporate politics is they are not used to it (and they will be exposed because professor).

OTOH I think they can become more arrogant when they are back to the uni, now that they have seen both worlds

How did that affect getting tenure? My experience watching my advisor go through that process is that an industry stint would negatively impact the process.

There are a lot of variables, but from personal experience it also depends on how you talk about that experience in your tenure dossier. I was able to spin a research finding into a commercial product. Due to intracompany politics, that product never shipped. But my tenure committee talked glowingly about my ability to take a research idea and polish it into something that a major software company would pay me to commercialize.