Seems to me the big problems are:
a) many posters here have danced with each other before. Old wounds, old spites resurface.
b) most subjects have been done to death with no progress - people are not open minded, nor admit when they're wrong, nor are interested in having beating the same, old, dead horse.
c) the internet encourages snark and rudeness. Most cannot resist, even if they sometimes veil it quite well.
No answer, imho.