Yes, Shlomo caused many people to become frum. However, what level of frumkeit did he lead them to? One where they think mixed dancing and touching people of the opposite gender is allowed?
Someone once asked him why he felt it was ok to touch women. He replied, “If you see a woman drowning, would you hesitate to save her because you can’t touch her? Of course not. Nowadays, the entire world is drowning.”
Obviously, he was missing the boat with his reasoning. His intentions were good, just his methods were lacking. They say he was depressed also for years. When I was in yeshiva, there was a question whether it was ok to listen to his music. The thought was that since R’ Moshe even had a teshuva on it, maybe it should be avoided even though R’ Moshe said it was ok (kind of like Cholov Yisrael). One Rebbe told us that he heard from his Rebbe, R’ Mendel Kaplan, that it was muttar to listen to Carlebacj music, but that doing so would get you depressed, as Carlebach himself was depressed, and it went into his music.
The Rosh Yeshiva of my yeshiva said it was fully muttar, by the way, but that we shouldn’t think Carlebach was a real Rabbi – he said straight out “He was a hippie.”