On the contrary, genres are very helpful. They provide essential wayfinding to indicate that if you like A, you might like B, and if you're interested in artist X, he operates in the same sphere of influence as artist Y.
That genres are continually and intensely argued over, and chronically subdivided, is a nuisance and navigating them can be a chore, but if you can stay above the fray fighting over the distinctions it can help prevent spending a few hours digging through stacks of music that you could've known you'd never enjoy listening to.
Sorry, I meant to clarify, never particularly helpful *to me*. (Relaxes in his kinda nice office chair, a little tipsy from Chinese new years drinking.)
I end up just chasing interesting leads from things I hear on the radio or in stores though. For me music is a process of fun discovery; I generally love finding obscure and very off-beat stuff.