Why do you all want so many Demigods? I have been playing quite a while now but I haven't even tried all DG builds yet. Each Demigod gives you about 3 solid builds and I still haven't tried them all yet.

"Quite a while" can mean very different things to different people.  I've been playing since release (which I'd say is quite a while) and I'm having trouble thinking of a build/map combination that I haven't played yet.

And I'm hardly an obsessive player.  I'm sure other people who play it regularly have exhausted the current options far more thoroughly than I have.

Difference is probably in the reason why people play. I play for fun, and want to try all builds (eventually) and find the formula for success with that build. And just play every build often enough to feel that I've seen all the fun things that that build has to offer. But probably 99% or more of the people only try builds because they want to win, and when they find a build which they can win with they won't try anything else.