Most psychics are obviously phonies. But I believe some people truly have psychic abilities (though I'm willing to bet very few actually become "psychics").
Pyschic phenomena is very personal and emotional (thus, I can't see people who are gnuinely psychic being able/willing to focus on it daily and make it a profession... it would rip them apart and drive them completely crazy). What they can detect is generally more of a feeling, a sense of understanding, the "spirit" of a time or situation, so to speak. Some may be able to see people and places and things, but still very much focused on the ethereal aspects of those.
Thus, lottery numbers probably don't cut it. They just aren't "important". The whole idea of being "psychic" is based on intuition, which is emotional in nature... Some people are clairvoyant enough to pick out exact facts and details from that emotional realisation, but I don't think there are many cases when lottery numbers would fall into that.