This thread should be titled "Asshole pushes Asshole, yelling ensues".
I don't think this has anything to do with "trail runners", "hikers", or "mtn bikers". It is people with bad manners, no common courtesy and a people with a big chip on their shoulder.
It is my opinion that both parties suck.
Yup. 98% of all groups are reasonable people. 2% of all groups are jerks. I had many pleasant encounters with families, hikers, trail runners and other riders on Seymour yesterday. I've also had unpleasant encounters with members of all the aforementioned usergroups.
Also, what's with all this talk of 'guarding the lane to the left' etc? Are people really in such a rush that they get upset at having to steer around someone who was inadvertently blocking their path on the climb up? I go to the forest to escape such stresses. If I have to turn around someone's bike/dog/child etc it doesn't bother me in the slightest. Smile, laugh about it, say hi, and go on your merry way.