The beauty of Trump is his transparency. He has made several broad promises and spends more time diverting attention from his failures and lying about successes than he does leading his country.
He promised a wall, at somebody else's expense, but when Mexico didn't roll over he started a trade war and claimed it was his plan all along; that Mexico would not pay directly but through tariffs and taxes. Sadly, he failed to hoodwink Congress and is happy to throw federal employees under a bus to demonstrate his ability to throw tantrums. Far from showing decisiveness, he is following that much-loved EU habit of holding vote after vote until he gets the 'right' result.
He is draining the Washington swamp, as promised, but only by his former business associates getting exposed for lying and cheating, what he himself might call 'the art of the deal'. He might not have been caught himself, but the stench around him is so strong that he will be. Not the victim of a witch hunt, just a very naughty boy.
Now he has made a second pitch for the Nobel, furious that a Democrat got it but not him. He has messed up so badly in Syria that the only remaining extremist stronghold is the one area he declared free of them. He returned from Singapore congratulating himself on his achievements, seemingly oblivious to the fact that Kim was the only winner. Now he has gone to Vietnam and failed again.
This is where his true nature shows through. His world is composed entirely of and / or moments, good or bad outcomes. Where other politicians would be able to sift the wheat from the chaff, Trump throws them both out or keeps both. Failing to do any reading about the context on the peninsular, he thinks North Korea having nuclear weapons is bad. He puts that to Kim, who says "But our neighbours, North and South, have them. How can we be safe without?" Trump has no answer but knows he has stuffed up, so his response is to lie: "Kim said this but I said that". The lie is blatant; he simply switched roles, claiming Kim's stance as his own and vice versa. There is no way Kim would leave himself vulnerable to a nuclear-armed South Korea, but Trump could only see it in US:PDRK terms.
Trump is not criticised "no matter what he does". He is criticised precisely for what he does. He could do differently, but refuses. And there are enough pro-Trump media outlets that he is unable to consider the alternatives, because it is their criticism that he really fears.