@The Proctor, I don't know if you're still interested in the 'Latinx' question, but I wanted to add my two cents into the conversation. Feel free to give me time clocks.
The basis behind this is routed in the western academia idea of control through language. The basic gist is that, if you can control how people speak, you can control how they think. There's been a movement to try and get rid of all forms of 'gendered' language in English, ranging from introducing gender neutral emoticons/emojis to politicians going out of their way to avoid using phrases like 'ladies and gentlemen.' The problem is that this form of language control only really works on languages where gendered nouns aren't built into the actual vocabulary like English. Spanish, one of the most commonly spoken languages on the planet that isn't some dialect of Chinese or Indian, has masculine and feminine ways of writing and pronouncing words, specifically nouns. With gendered language built so deeply into the roots of Spanish, some 'language specialists' (mostly upper middle class liberal arts professors) came up with the idea of introducing a third, gender neutral way of writing and speaking Spanish. Thus, Latinx was created to try to 'capture' the Spanish language much like the English language has been captured.
The problem? Most Latin American countries, which these academic types thought would embrace and adopt this bastardized form of Spanish, told them to fuck a cactus. It turns out that trying to convince a part of the world which is traditionally Catholic (with all that entails), that their way of speaking is out of date and that you need to change the entire structure of your language (which is considered to a cultural foundation in many parts of the world) isn't a good idea. The fact that part of this was pushed by upper class Latinos (who have probably never stepped foot in any other Latin American country that didn't include a Sandal's Resort) only made the rejection more visceral.
TLDR: Academics tried to explain to a demographic why their language is sexist/racist/homophobic/etc. and were promptly told by Latin American moms to shut up before they whip out the chancla.