Actually, I think M even admitted the band weren't that good live in terms of musicianship
It was a lack of ability, as to why the songs sounded different,a lot of the time. It was awful what they did with the Suede cover. M's voice was great but the band were a bit shite.
They still made good studio records but live it became more of a rougher, NY Dolls kind of "event" rather than polished gigs, great gigs mind.
I myself enjoyed the shows, but I could understand the fans not liking it. Its often been the case post Smiths , that M could do way better, if only he had a better band and thats what annoyed people, the frustration of underachievment
Another term for 'different interpretation' is 'inferior technical ability'.