Re: "There is no inventive concept that provides something more than the abstract idea itself"
So I strongly disagree with your claim that the patent office shouldn't ensure that the patent is completely valid before granting it!
I certainly agree that in an ideal world that would be the case, and the money fairy would pay to make it happen.
In the real world, a patent office doesn't have unlimited funds to play with and doesn't have an army of competent specialist staff to assess the merits of patents in every field. It's not a matter of what should happen, it's a matter of what patent offices can afford to do.
As things are, patent offices are just not able to validate patents, so we cannot realistically ask that they do. We can only require those who register patents to play fair, and penalize them if they don't. We should do that.
This works better under legal systems in which the winner of the case can expect to have their costs paid by the loser than under those in which only the lawyers stand to make any money.