A Brief Rant-Golf Etiquette

I played 18 holes of golf today. I did much better on the back 9. The front 9 was pretty much a disaster. But, I ran into the same problem that I've been having as of late, whether I play with my usual partner or alone.

Will somebody please tell me why people on the golf course (as of late, it's been primarily old guys) are so dead-set against having faster people play through? I just don't don't get it. I thought that was one of the primary roles of golf.

Apparently not.