Everyone says that and just assumes that being a governor gives you all that experience - and that not being one means you don't have it. True sometimes, but not always. Moreover, the country does not need an "executive" now - we need an inspirational leader. Not saying Walker can't be that, but he is from Wisconsin, which means there is an inner liberal in there somewhere. But let's be real - Walker is saying this in a self serving manner to put himself above Cruz and Paul - figuring he'll beat Krispy and Jeb.
I have no doubt his comment was self serving, and I also generally agree with the other points you raised. That being said, in judging Walker’s effectiveness as a leader in Wisconsin who is able to push through his agenda, I think one of the main factors in his favor is just how many liberal he has been able to piss off!