I wouldn't date a pot head because we know what that means, but my boyfriend smoked weed faithfully.
He has a job, a car, goals, etc. He doesn't really even get high when he smokes.. he uses it for anxiety, but it just got bleh after awhile. That's why he stopped because the use for it was becoming pointless. I don't smoke at all.
As long as he/she works too and is successful then sure I don't mind - hell we'll be smoking/eating it together. But if their life revolves around it to the point they do nothing but weed - have no job or anything aka they're a deadbeat, then no.