Actually, he went there to do exactly what he was observed doing: Cleaning up graffitti and garbage, offering medical assistance, etc. And no doubt also to ‘protect people’, which is why he stupidly brought that gun.
This is what happens when riots are allowed to run without the police asserting control. You get a rise in armed citizens doing the job the cops should be doing. When crime was rampant and police ineffective in New York pre-Guliani, it caused the rise of groups like the Guardian Angels and fantasy vigilante movies like ‘Death Wish’.
If you don’t want more citizens with guns showing up at riots, stop defunding the damned police, and stop preventing them from using their tools to contain riots.