Kurt did skate clean LPs many times, IIRC- occasionally with very minor flaw.
Worlds 1988- his only flaw was a turnout on the landing of the quad toe (first ever in world championships), which was ratified.
Worlds 1989- He two footed the quad, but rest of the program was clean.
Worlds 1990- I believe this was clean. I remember that Viktor Petrenko had a strong skate with a 3A-3t combination, but Kurt skated better.
Worlds 1991- I believe this was clean. His main rival Petrenko had a wonderful skate, with just one mistake, and although I thought Petrenko should have won, I could see why Kurt won.
I don't remember the GPs at all. He did not skate clean LPs in the 1992 & 1994 Olympics, and I don't remember the 1988 Olys. So if you meant the Olympics by "major competition", your statement is correct.
As a 4 time world champion, I think it is reasonable to say that he was the greatest man to never win the OGM, although my vote went to Brian Orser because he was Oh so Close both times to the OGM.
I think Kurt is a great skater, who really developed his artistry in 1993 and later as a pro he was one of the best artistic skaters. He had wonderful footwork, probably the best among singles men. However, I must admit that I am a little surprised by how many more votes he got compared to Orser, Stojko or Lambiel.