When someone perceives that other people dislike them, they might lash out and set up a self-fulfilling prophecy. It's not the first time I've seen this happen on this site. One guy even claimed to support FT26 just to push our buttons.
It's ultimately a defense mechanism and the root of the problem will be frustration with one's social experiences.
I like to think that I don't hate anyone or anything, though sometimes I involuntarily make an exception for specific people who tormented me in childhood, covered up the abuse and then went on to live happy lives while I rotted in poverty, isolation and mental illness. Being cool with that level of cruelty is beyond me.