He has almost never had a challenger who had any significant drawing power whatsoever. Everyone he fights is a complete nobody so he never gets a big win in a big marquee matchup. When he fought Cruz in the UFC they were both fresh and not draws at all. Since then the biggest name is Joseph Benavidez.
At this point I would say his career is pretty comparable with Andersons. Why was Anderson a way bigger draw? He fought guys like Rich Franklin, Dan Henderson, Forrest Griffin, etc before he really blew up and could carry a fight himself against a no name. People tuned in to see not only him, but his opponents. Winning those big matchups makes a star. DJ will have none of those at 125. None.
The only matchups at this time that could launch him into stardom are at 135. If he refuses to go up that's his choice, but he'll never get rich.