But the people who use 'he' or 'she' don't normally object when others use "she, zie, hir, they, em, ey, eir, or whatever"...well if they do it's usually only because they believe V is a 'he' or 'she'.
It was the OP, who said "I've seen all kinds of nonstandard pronouns used to refer to Vaarsuvius. Stuff like "Hir" "Vim/Vis" and "Shim". These stopgap pronouns are awkward, confusing and ugly. We should be using Spivak pronouns..."
It's the OP who had a problem with the usage of others. It was the OP who suggested the conformity of the nonconformist. The suggestion was phrased mildly but the suggestion itself carried its own "hostility", as you call it. It's no surprise people responded the way they did.
I know not what [grammar] course others may take; but as for me, give me liberty [to use the pronoun as I see fit] or give me death [of intelligent discourse]!