They are clearly following another vehicle at a safe distance and riding legally. There is no shoulder in the photo, just the sidewalk. It's pretty doubtful that the local law allows bicyclists to use the sidewalk.
Now, I would ask what if instead of bicycles, they were two small motorcycles riding side by side and they happen to be slow drivers. Pretty doubtful there would be any argument in a public forum.
So, the anger is not with the clearly legal and safe bicyclists, nor is it with who owns the road, it's more a question of involvement.
The bicyclists own as much of the road as a motorcycle rider, car driver, pickup or 18 wheeler drivers for that matter. All residents pay for the road via taxes.
If a bicyclist breaks the law, they need to be held accountable with a traffic violation.
If they're using the road safely and as directed by law, then what is the problem?
If the residents decide bicyclists must follow each other in single file at the edge of the road, the residents would see the law changed and the bicyclist would obey or get a ticket.
It's not the bicyclist's fault if the police do not ticket them, talk to the local police. And if someone would petition the local government to enact tighter bicycle laws, it would benefit the bicyclist most of all.
Beats looking like a whiner any day.
Micheal D. Knehans