I think the issue is the choice of word 'unwelcomed'. Aggressive may be better in capturing (what I assume is) the author's intent, but I would still find it a bit lacking. Some homeless behavior isn't aggressive but is unpleasant enough to cause people to make changes to avoid it. How do you describe such behavior without also describing behavior that a different group may choose to avoid that they really shouldn't be avoiding?
Maybe we can define it as aggressive or unsanitary. Not perfect, but it is the closest I can get without shooting over the intent.