I don't think most people riding a bike feel compelled to be ambassadors for cycling. Simple as that.

He must have felt endangered and had a rush of adrenaline and then used some of that up cursing at the OP. Been there myself. I remember almost getting run over by an idiot on a cellphone who failed to negotiate a turn and ended up on my side of the road going way too fast and only one hand on the steering wheel. I was so wound up I was cursing at full volume for the next mile. Same thing happened once when I was right hooked. By the time I chased that person down I was still shaking but didn't curse.