IMHO there is difference between using his songs (where Rav Moshe’s teshuvah says its okay) and advertising a “Carlebach minyan” or a “Carlebach Shabbos.” The latter, which smacks of a celebration of the man, bothers me a good deal.
That being said, a person can do terrible acts of rishus and also do incredible acts of kedusha. People are complex, they have great capicity for holiness and great capacity for evil. And most people do both great acts and bad acts. It isn’t all or nothing, one campe or the other.