I don't consider myself a cyclist! I'm more of an old man who rides a bike daily or tries to for exercise, and I prefer the greenway trails or MUPS over riding on the street.
Unfortunately I see much of what you are talking about, and what annoys me is the cyclist all decked out in their kits riding in a group or single and speeding around turns with little regard for those walkers, and some seem to get annoyed that they had to slam on their brakes to avoid someone or even me because I may not have been going up to their speed.
Don't get me wrong it's just not the "cyclist" but everyone needs to use a little common sense and a whole lot of just being considerate of others, and we can all enjoy those nice days.