do the types of gamers that make these characters do so because they want to be able to breeze through the content, or because they want the challenge of seeing what they can survive?
Maybe, maybe not.
"I optimize because my last GM was a real killer and I just want to survive so I can role-play one character over a long period of time and develop some real depth."
"I optimize from multiple sources because I really wanted to play a finesse-duellist-type, and that concept doesn't work well using only Core. If I don't shop around for the best feats I'll be letting the group down."
"I optimize because the character concept I had was someone who hates violence, yet is incredibly good at it when pushed."
"I optimize to make the most powerful character possible because I like winning and hate losing. I hope the GM doesn't spoil it by turning up the opposition to neutralise my choices."
"I optimize to make the most powerful character possible because optimizing is fun. I hope the GM makes some really challenging encounters so I have to think tactically to survive."
"I optimize because the rest of the group does."
The most important rule is: