Pissing off your allies is good because if they're happy, that means you didn't squeeze them enough.
It's the reason a "trade deficit" is seen as a bad thing by him. Trade deficits are the result of a mutually beneficial transaction, but that's not enough for Trump. It can't just be mutually beneficial, it has to be beneficial more in our direction than theirs.
Or look at how he treats contractors. He hires a person to do a job, they agree and deliver the work, and that should be the end of the mutually beneficial deal.
But not for Trump, his MO is to stiff contractors, force them to sue, mire them in a legal quagmire, and get them to settle at a loss. This is the kind of deal Trump likes because it's a win for him -- he gets the contracted work at a fraction of the price; and a loss for them -- they probably wouldn't have agreed to do the work had they known what they were in for upfront.
Is this a great way to run the largest economy in the world? Of course not! But that's how it's happening now because that's the kind of guy who is in charge.