You're on to something. I recall how the Kent State incident put a major damper on anti-war (Vietnam) protests. These things are only courageous when there is serious risk of injury, imprisonment or death involved. Without serious risk, it's only a lot of pissing into the wind.
As an aside, I remember a lie-down protest in front of GHWB's White House at the start of the first Gulf War (January, '91). Hell, the cops simply stood by and waited for Nature to take her course. After a half-hour or so of lying on the cold, cold pavement, the protesters had to get up and go have a hot coffee at the Presidential McDonalds.