Pragmatic answer: because it crosses some threshold where it's deemed I'm dressed appropriately at work and a normal shirt wouldn't. > The collar is in place t

Pragmatic answer: because it crosses some threshold where it's deemed I'm dressed appropriately at work and a normal shirt wouldn't. > The collar is in place to hold the tie, you don't need a tie, you don't need a collar, so don't wear one A collar can also be popped to provide extra shade to the neck, it has it's own functionality independent of the tie. I'm not sure if these execs are getting enough sun that it matters, but I certainly do.