It is true that the 308 winny is more limited in its abilities versus some of the other more potent cartridges, however the 308 does just fine out to 600-700 yards for deer size critters provided the nut behind the trigger and the bullets used are of good quality.
Of all the bullets I have used out of the 308 on game at LR I have been most impressed by the Nosler ACCUBOND bullets. I have used the SMK's, AMAXS, SCENARS, and the ACCUBONDS. I have used many different weights as well. The critters that died the fastest and had the maximum blood loss were the ones shot with the ACCUBONDS.
By using the right bullets, you can muscle up the smallish 308 win. By practicing often you will become proficient with it to make clean kills to 6-700 yards. The nice part about the 308 is it is much cheaper to operate which allows shooters to really get to know their rifle and where the 308 lacks in horsepower, it makes up for it in accuracy. I have also found that in the field when you cant get a perfect position it is harder to get a super mag to recoil the same and thus impact the same as I do on the bench at home. The 308 is so much less finicky that it seems to hold the same zero regardless of my position. This to me is a huge benefit.
In short, no I dont think you are thinking too highly of the 308 so long as you stay within its and your limitations.