I am guessing that with him, being in the movies and on TV shows is a higher priority. Country legend Dwight Yoakam is no different, just the other way around. He's done plenty of acting, but at the end of the day, being a singer/songwriter is his top priority.
There is a lot of musical talent out there, it isn't rare. the industry is mainly aimed at the adolescent female market, and Schneider didn't click with that demographic. They make the 'superstars', and tend to follow the same ones throughout their lives, which is why Taylor Swift is a super star and will be for many years to come, as will Justin Bieber and others will be, and the Beatles still sell records..