Correspondence Chess, Turn-based Chess, Standard Chess, Lightning Chess are all fine games, each in their own right. One is neither better nor more intellectual than another. They are all simply different ways of playing the same game, each of which has its own aficionados.
Many great masters of chess were also speed chess/lightning chess players of outstanding ability : Petrosian, Fischer, Tal, even Karpov for examples. Above is pictured Reuben Fine who was the US speed chess (10 sec./move) champ in 1942-43-44-45. I can only say, play whatever you like, but don't begrudge or belittle anyone for their own personal preference.
Vive la différence!
I was referring to correspondence chess, not 20-minute games. 20-minute games are the best I can hope for on most chess servers, but not my ideal way to play.