Why not both?

I had a boss who was a VP in sales. His philosophy was "On the days I go in late, I make up for it by leaving early".

I'm guessing that sales is pretty different from typical software dev, in the sense that sales productivity is very measurable.

That probably sidesteps a lot of the guesswork about what makes a person most productive.

Yes and if you're hitting or exceeding your sales goals, your boss won't care how much you are in the office. For at least some sales work, a substantial portion of it may take place outside of the office anyway.

This is pretty consistent with my experience with both salespeople and VPs regardless of department.