Pete's peak years, 93-98, does not coincide with the Borg-Connors-McEnroe-Lendl era or the Federer-Novak- Nadal eras. The fact IS that Pete won 14 slams, when he won them is not really important.
Indubitably, Sampras won his Slams when he won them; he did not win them at some other time.
Sampras played in an era of specialists and 16 seeds at majors. Winning 3 majors in a year was uncommon.
Well, was the gentleman saying that 1993-98 was an "era" in five years? An era in five years? Was he saying this "era" was uniquely resistant to winning three out of four? Either assertion would be odd. But if that was the assertion then my point that no one could win three Slams during those years precisely because Pete was the best player is valid, if boringly obvious. Pete could not do so - not in the sense of win three out of four Slams. Kind of hard to anyway when there is one at which you ain't got no chance in heck. He could not win three of four. That is just the record. And if Pete was going to win two each year (roughly), then of course the five-year "era" would be particularly resistant. Hmmm.
If, on the other hand, the poster meant an era a little more like an era, then the inclusion of these other players is correct. Perhaps not the 1950s, I don't know. But "era" according to Oxford Dictionary, means "a long and distinct period of history." At the least an era is a generation - at the least. A generation is now generally thought to be about 30 years - 25-30 years. In the Open era pre-Sampras No. 1 (1968-1992), three out of four was done eight times.
Maybe he did not mean "era" when he wrote "era". Maybe he meant the decade of the 1990s. That is fine, I guess. I don't know as 1990s were so much more resistant to a player winning three out of four, but fine. But he said era, so I discussed era.
Finally, I tried to point out that Pete's 1994 and '97 were quite splendid from a historical perspective. In 1997 he became only player to win YEC and GSC in same fortnight. That achievement is surely Slam-like. I'd say he won three of five that season. Petros "Rocked".