Pedestrians here are not ‘behaving badly‘ they are simply ignorant of the expected conventions of MUP Trail Etiquette. But it must also be the case that bicyclists in that region of the country do not ‘pass on the left‘. Otherwise the ‘stupidity‘ is being shared by cyclists and pedestrians alike.
My suggestion is to take a deep breath and slow down enough to not pass pedestrians with less than what appears to be a 3-Feet Distance. We sorely need that sort of law to keep cyclists and pedestrians from colliding quite so often.