I think the seeming lack of bad will against him stems from the fact that he didn’t kill anyone but himself. Just a righteous (or rather self-righteous) rampage of property damage.
…except that he absolutely intended to kill people considering the arsenal of firearms and shooting ports in his contraption.
Frankly, I wouldn’t be surprised if developed countries start refusing entry even to educated Americans on general principle. We fucking suck, and we’ve burned a lot of what little good will we have as a people.
And even if you did get in, you would probably have to deal with that animosity from the locals.