So I've been noticing this, but why do so many cards have the hottness level of "xxx"? It made sense when the IstripperXXX had such a level and even some of the regular stripping cards just have the level of "full nudity" both of which makes sense. Why would cards that are essentially normal stripping cards be given a level of "xxx". Any ideas?

Because there's something in at least one of the clips that called for a L5 / XXX rating
Even if just for a moment

Heavy rubbing to apparent orgasm........
Finger dipping........
Something along those lines