This Huffington Post article (http://www.huffingtonpost.com/brian-joseph-davis/mfa-programs-_b_929183.html – links aren’t working today) argues that they are.
In my opinion, the most important pieces of information writers should get from such courses are:
Spelling and grammar (don’t laugh; it’s necessary)
The ability to follow submission instructions (so, so necessary)
Industry manners – eg don’t ever reply to a rejection
Some realism about (a) How long things take (b) How much writers earn, and (c) How few unpublished novels ever get published.
In my (reasonably limited) experience, none of these are taught in writing courses. But some other useful things are. Perhaps more importantly, you meet other writerly types, and may end up with a decent critique group.
Pictured: not a decent critique group.