I never seen any latino, (even the progressive and left leaning ones) use latinx expect in a joking matter or how they loathe it.

Since your profile lists France, I will take this as a genuine non-rhetorical question.

Because there is no need. Spanish is a gendered language as you probably know. Sometimes the plural is "male", sometimes is "female". That's how the lenguaje works, it has never been about sexism.

But as Fawful says, the "liberals on collage" found a way to be ofended, so they complain that is sexist to use the everyday plurals. For example:

Las compañeras = The classmates (If all the classmates are female).
Los compañeros = The classmates (If there is at least 1 male classmate).

So now we are suppose to speak in this way: "where are your classmates(F) and classmates(M)?"

Sounds unnecessary in English right?, so does in Spanish.

Then comes the worst part, the "e". They also argue that instead we should get rid of the gendered part and replaced with a neutral "e". Effectively guttering a language so they can brag about their moral superiority and solving sexism by doing this.

They argue that languages changes over time, so there is not an issue doing this.

Yes, languages change over time, but they do so in organic ways to solve a need. This is not organic, just some people inflating their egos thinking that they solved sexism by tearing apart our language.

TL;DR No need, our language works fine as it is, use latinos(as) as needed.