As far as marketing goes, G&L never had a broad enough dealer network to compete with the likes of Fender. Even today people complain that they can't find a store that stocks G&L.
I was at the downtown Boston GC this week. The bass room had maybe 60 basses. Loads of Fender, Musicman, Ibanez, a few Schecters and a few Gibsons. Not a single G&L bass. Same in the Peabody MA GC. No G&L's.