I really don't think the EPIC 4G's battery is all that bad. With SetCPU, Voltage control, etc on the custom kernels/ROMs, the battery life is actually usable.
But in comparison to some of the other Smartphones I've played around with, Droid 1, Droid X, Thunderbolt, Mesmerize, EVO, iPhone, etc, I'd say the Epic is actually better than those above...
I am, for the most part, all about keeping the phone simple and functional over bells and whistles. I did however flash the H.R. Giger Theme over the top of SFR, and I have been enjoying it the past few days.
So bottom line, people do what they want with their Android phones. Most people are most likely happy to get a charge to last for 8-10 hours (work, school, etc.). I'd rather have the option, and not use it, versus not having it all...