Not true, Sublime has countless good tracks, a lot of which was not included the two albums they produced and released after the singer died.
Sublime hasn't fallen off the map at all, the band broke up when singer died almost 15 years ago but they are still widely popular on the West Coast. They introduced a new style of music "Reggae Fusion" to the US which a number of modern bands have adapted and there are five Sublime-tribute bands currently touring. They are just as popular and respected still as bands like Nirvana and the Chili Peppers and are still present in culture in California.
They aren't one of those "15 minutes of fame" bands.