"Most" is a weasel word. In fact, the opposite has been true in my experience: Among the regexps that use ^, $ or ., at least half required s or m. I don't have a good idea of what the percentage would be if I included those requiring x. I don't know if the rest of the world is in the same boat or not.

Anyway, I do see your point. There's definitely value in being consistent with the rest of the world, but there must be a point at which world-consistency is outweighed by other concerns. I wonder what it takes.