You always diminish Sampras' accomplishments. I wonder, are you Andre Agassi in disguise?
Sampras did not set out to win every tournament he entered or to have internet geeks salivate over his percentages in future years. He set out to break all important Open Era records, and by the time of his retirement, he had done so;
- 14 major titles
- 7 Wimbledons (Note that, at the cathedral of tennis, Sampras was more dominant at his peak than any player before or since, male or female: no-one else has ever won 7 out of 8 singles trophies at SW19)
- 6 successive years as world #1
- 286 wks as world #1
- 5 YECs (I concede that he only tied this record, which Lendl jointly held at the time as well)
Sampras' style of play was of course focused on his holding serve, and he knew that he often only needed one break per set to win. Thus you saw him win more often by scorelines like 6-4, 7-5, 7-6, as opposed to the likes of Borg and Nadal, who surely had far more 6-0, 6-0, 6-1 type scorelines. This doesn't mean that Sampras was 'less dominant' though, he knew exactly what he had to do to win using his imposing serve-and-volley style, and didn't care about winning by huge scorelines.
On a more macro level, he only cared about the stats which I posted above, not about racking up multiple minor titles like Connors and Lendl. He conserved his energy for the big events, and for periods when he could wrap up the No 1 ranking (i.e. at the end of 1998, entering tournaments to ensure he finished ahead of Rios). So I think it's highly unfair to criticize his comparatively "low" number of tournament wins or percentage W/L record.
Again, who cares about percentages? Djokovic in the last five years has won 9 slams and finished world No 1 four times out of five, which I'd say is slightly inferior to Sampras' best five-year period from 1993-1997, when he won 9 slams but finished world No 1 five years in a row (I know this is debatable, but the point I'm making is that you can't use your beloved percentages to push the likes of Djokovic far above Sampras).
There is much more I could write about Sampras, but I understand the OP's point of view (on all surfaces bar clay): there is no-one you would rather have playing for your life, to have the confidence to pull out a second-serve ace, or a running forehand winner, than Pete Sampras. Maybe Pancho Gonzales could compare historically but that's about it.
I rank Sampras as the third greatest player of all time, behind only Federer and Laver. Only his lack of clay prowess prevents him from being right up there with those two...