what are restrooms for?
Who said he was JUST there to use the restroom ? The reporter ? (yes).
That is not what he was doing there. He was sleeping on the bench, which is against the law. The officer asked him to get up off the bench and leave the area. This wasn't the first time he had dealt with this derelict. The derelict responded with refusal and profanity.
It had nothing to do with going to the restroom.