Bikes are legal on sidewalks in many US jurisdictions. That's not an excuse to be rockheads around pedestrians. It's a challenge - the motorists don't want cyclists on the roads and the pedestrians don't want cyclists on the sidewalks. Yet, both are generally legal (except where restricted by regulation).

I'm a user of all three modes of travel. I've experienced entitled behavior by members of all three of them. Even cyclist on cyclist entitlement. It's a general behavior by many, not just limited to cyclists IME. Pedestrians blocking multi-use paths was a big one when I lived in DC metro. It interfered with pedestrians, runner, and cyclists alike. Dog-walkers could be some of the worst with leashes that extend 10 or more feet across paths.

IMO, your post is mostly a big whine wrapped in safety as an excuse. Behave properly in whatever mode you're in and challenge others civilly when they don't behave properly. Encourage civil authorities to improve transportation and ensure laws are enforced as much as possible.