The reason why he managed to win the calender slam is because of the incredibly weak field. Same as why Sampras won so many Grand Slams. Although I have to admit that Sampras's competition was head and shoulders above Laver's.
Well one has to wonder how Pete would enjoy having 3 slams played on grass.. But I don't know. Tough to top a calendar season slams.. And Laver certainly didn't play tennis scrubs to get it either.
Laver dealt with a buttload of talent as I mentioned before (Ashe, Newcombe, Nastase, Borg, Pancho, Connors, and Rosewall).. I wouldn't call that field "weak" by any means. He played some of the all time greats to ever play the game. Plus he was banned from playing the majors in his prime and STILL won 11 slams. Had he played them, he probably has 20 slams.. Maybe more