Part of the issue is people are used to simpler statements. One enemy at a time. One condemnation at a time.

Also they are used to how politicians typically do whatever necessary to appease their constituents till the horse is dead. Not saying this is bad, but that's the expectation and one he doesn't follow.

I also think he's not attuned to people's sensitivity toward race.

I said no new taxes. No new taxes. No taxes. I won't raise taxes. Taxes will not be raised. Over and over and over and over.

Not being a pol hurts him here in that he does not get that aspect of governing.

You don't just do what you think is right, you have to continuously signal your intention, otherwise your intention is suspect.

Congratulations, you're not paying any attention. He notably refused to condemn them initially, then released a textual statement condemning them days later in response to criticism, immediately walked back his condemnation in a press conference, before condemning them again. If you read that as "He condemned them! Twice!", I don't know what to tell you.