We never said anything about the promises being "harmful". It's also not his place to decide what is/isn't harmful, he was elected based on certain premises and promises of certain actions. Of course, he get's to interpret stuff/meaning, but directly
not doing the things he promised without a valid reason to explain is quite immoral.
Now if you want to argue that "he has a good reason, we just don't know it" then you're pretty much conceding that your people aren't really running the country a la democracy. It means that they're picking a president on completely imperfect information, and have nothing but promises and character to go by. Heck, they can't even rely on the candidates keeping/breaking their promises.
Positive policy changes - good. No one is saying that he did only bad things or anything, that's not being discussed at all, and neither is his character or how good of a person he is. That's like saying: "Yeah, sure, my husband beats me... But yesterday he said he loved me, and he bought me flowers. I'm sure he beats me for a reason, and I don't know what information he bases my beatings on."
The example is ridiculous, but it shows the irrelevancy of good deeds outweighing the bad, through extreme points.