Bikes aren't like food, water, or shelter. It's not inhumane to keep someone from riding a bike on a road where it's not safe to do so. That said, I'm certainly much more sympathetic towards those who are riding a bike because it's their only transportation. I just think that situations where someone's need for such transportation outweighs the inconvenience and risk they're causing to the public are rare. Put another way, your need to get somewhere is not more important than my need to stay safe on public property.