I used to work downtown, and still do sometimes. I actually hang out in deep SW which is why I might not see them as much. I also work on swan island where the homeless have set up an entire camp.
On swan island they don't harass you until you get to mlk.
Of course on the max you're gonna get harassed. Buses too. But not every line.
What I did was buy giant headphones. I get harassed much less now.
Also everyone keep in mind, some of the people harassing you aren't homeless and are pretending to be. I used to work at the downtown safeway and I've seen people hop out of cars and get picked up after they collect their scrap change. I even used to know someone thru friends who was technically couch surfing but she would go beg for change and food samples at my store. She even had food stamps.
There's just a bunch of freeloaders here.