The BG series has always been a story about the "chosen".
I like that this time we don't start by killing rats, you don't have to start the story always by being nobody.
And the fact that the campaign is intended for characters with a higher level does not matter. A good story shouldn't be limited by mechanics.
Well you kill better than rats at the beginning of BG2 and I don't even mention ToB !
I don't think it' about mechanics, I think it's about realism (even if I personnaly don't really care at the moment).