I take it you didn't watch the video. Watch it first, then comment on what's a more pressing issue: composting or thousands of people living under the bridges and shooting up heroin.
I live in Seattle and have watched that hackjob of a video, they've fenced the underside of many bridges that homeless used to camp under, most recently the West Seattle and Ballard bridges have been fenced.
Your obviously disgruntled, move somewhere else!