It's noticable that the Hexblade and Warlock are two classes with strangely low skill points relative to their number of class skills.

Warlock doesn't suffer too much here, simply because Warlock is stat-independent, can afford a reasonable INT without gimping more core abilities too much and are supposed to be mostly human anyway.

Hexblade, on the other hand, needs good physical stats and CHR, so generally has to make INT a lower priority. Having so few skill points and so many useful class skills starts to hurt.