There are many gender-neutral pronouns, and people continue to develop new ones all the time. So why is singular they the focus of a blog on practical usage and user support?
First, from a non-scientific and non-random sample, it seems as if they is gaining ground and acceptance as the most popular and recognizable gender-neutral pronoun.
Second, although ‘they’ and its derivatives (their, they’re, theirs and them) are ordinary and familiar English words (unlike zie and hir, for example), users often receive comments from others who maintain that singular they is grammatically incorrect. In my view, the root of many peoples’ struggles with gender-neutral pronouns might not be grammar, but discomfort with difference. To claim that grammar is the obstacle is to avoid having to say that we are uncomfortable. A grammatical argument sounds reasonable. TIMP exists to ignite a different conversation about singular they: not whether it’s correct or not, but how to put it into practice and make peoples’ lives nicer.
Zie/hir etc. are unfamiliar words in English, and although they can become more familiar over time, they do not demonstrate this conflict in the same way that they, a familiar word, does.
TIMP recognizes that other gender-neutral pronouns are valid and wonderful, and that many of the practical suggestions on TIMP (like when to ask someone’s preference, etc.) are applicable to all alternative pronouns in English.