I have directed them here. But just think about it for a second, most of the guys I talked to don't make a lot of money. Most wont drop $600-$800 on used gear if they don't even know if they like it; if they even go through the effort of making an account, going to the classifieds, doing research, haggling with people, possibly slow communication, etc. Same thing with loaning gear.
It puts the potential customer at an inconvenience, that is the bottom line. I do not see how it could be too much work to have at least one shop at most major resorts to have one shelf of alpine snowboards. They could even brand it as a race or speed or slalom board to get peoples attention who may not know what an alpine snowboard is and brand it as a specialty board.