Gygax designed the Tomb of Horrors modules for two related purposes. First, Gygax explains, "There were several very expert players in my campaign, and this was meant as yet another challenge to their skill—and the persistence of their theretofore-invincible characters. Specifically, I had in mind foiling Rob Kuntz's PC, Robilar, and Ernie Gygax's PC, Tenser." Second, so that he was "ready for those fans [players] who boasted of having mighty PCs able to best any challenge offered by the AD&D game."
- Wikipedia,
Tomb of Horrors
Those were Gygax's stated purposes. His words. If you didn't get that, you'd kind of have to take that up with him.