If you want to blame someone for this farce, you should start with Norwegian Nobel Committee which gave Trump's predecessor Peace Prize mere months into his presidency, simply on the account of looking "cool" and saying right words during his 2008 campaign. In other words, more on the account what they hoped he would do rather than what he actually did. And the high expectations, naturally, weren't met, but the criteria for getting Prize was so lowered and with it, Nobel Peace Prize becoming so meaningless that even someone like Trump getting it could be reasonable prospect.
I don't need to blame anyone here, because I personally don't defend (or endorse) anything about the Nobel Prize.