Angry at Trump? there are many reasons - and if he lasts the course it would be a big surprise. But the problem with these 'Accords' is that they are reached in a very undemocratic fashion. No one voted for them, so it should be no surprise that they are abrogated without any input from citizens. The same can be said for Brexit - maybe there the Leavers won by too thin a margin to give it legitimacy, but on the other hand no one could vote in favor of 'ever-closer-union'.
Solution: give citizens say over all decisions.
Trump says U.S. to withdraw from Paris climate accord