I can't speak for the people you come across, obviously, but if you have a look at these examples you can see I don't think that is necessarily the case (just to clarify we're discussing other people's opinions here and not the validity of them).
ESPN Legends of cricket - Warne at 4, Lilliee at 6 and Marshall at 16
Wisden Cricketer of the Century - Warne, Lillee, Barnes, O'Reilly, Larwood, Lindwall all above him with Marshall only receiving 3 votes.
Didn't make it in Bradman's or Benaud's XIs or even the short list of the latter. My point is to repeat, from what I've come across, it isn't widely accepted that he's the greatest bowler (or even fast bowler) ever. (Obviously all those lists I brought are much criticised and are said to have many flaws, but again we're not talking about their validity here.)