But why would you prefer less over more???
Well less is more!
Joke aside, for example you'll find in PSE: DT, FF and Anal. It's a personal preference to enjoy those things. If someone don't enjoy or fancy it why would someone wants it?
Also most of the time PSE is more expensive than GFE and rightfully. So why would someone pay for more for something that someone doesn't want?
If there GFE and PSE are options it is for people to choose based on their own preferences ;-)