It's not that he attributes responsibility of the actual actions and things that happened to them to him being human, but the aftermath of the events and how he subsequently dealt with the losses that'd be linked to him being too human, hence Eleven. But the second is more or less the vein I'm getting at, since once he regenerates, it's implied that it'll be unlikely that he'll reengage on his old relationships with the same regard if at all, so Ten tries to hold onto those relationships through staying Ten.

Or you could just see it as the show being meta on itself and indicating that RTD's era was ending and with it, the characters and relationships and etc.