[rhyzomatic]

For points 1) and 4), just so you are aware, "they" as a singular pronoun has been in popular use since the 14th century. The idea that the "correct" gender neutral singular pronoun is "he" came about in the 19th century. I find it much harder to support the idea that "'they' is supposed to be plural" with this in mind.

[wildmusings]

Today I learned. Thanks for correcting me.