I can share my own story. I wanted a medium caliber rifle for target shooting past what my .22 can do. Also good thing to have if/when SGR (stuff gets real). I was basically choosing between 30-06 and .308, with some other potential choices further down the list (7mm Mag, .270, etc). I chose .308 because my research turned up that it had very similar performance to 30-06 in a smaller case, I preferred the short action, and it is a NATO round. I also like the potential to have a semi-automatic .308 in the future which shares ammo with my long range bolt action rig. That flexibility is what ultimately led me to .308.