They are acting as a group. If anyone within the group had stopped the others, I would agree with you in principal, even if not fact. But they didn't, they stood by and watched or cheered. They enabled.
Literally throwing shit is not peaceful protest.
Urinating on a war memorial is not peaceful protest.
Blocking access for ambulances - potentially causing significant harm or death - is not peaceful protest.
Ottawa has peaceful protests all the time - this is not that.
Its definitely annoying, and ocassionally lasted multiple days, but it gets support and doesn't potentially cost lives.
I lived in Ottawa for a lot of years and there were countless protests - but they respected the need for society as a whole to keep functioning (read: emergency services) and worked with the local police to make sure they were in the right.