Lol, if people remember that movie they should be old enough to read the class and spec descriptions. I also don't think people will confuse spec names in WoW with titles of bad movies, like The Beastmaster (note the lack of a space between Beast and master). Btw, there is no Marksmen (which is plural btw) spec named after a 2005 movie with Wesley Snipes. It's called Marksmanship.
BM has been OK as a spec name for more than a decade, it doesn't need changing especially since spec changes are easy and cheap.