It's not concrete allegations - it's many snide remarks about his fans touching him & that being his motivation.
For instance, from 1999:
Yet the fact that this…man generates any interest at all this far down the line of lackluster albums and gallingly ambiguous behaviour is a mystery...
The moment he appears onstage though, it’s clear there’s nothing noble here. Morrissey is an adoration junkie, plain and simple.
he clambers onstage to keep the unconditional love pumping through his veins...
The audience are, to put it bluntly, easy...
he feeds off it with guile... kicking off the set with a manipulative ‘You’re Gonna Need Someone On Your Side'.