Who exactly used it first appears to be lost to history, but the first known published academic appearance seems to have been in the Fall 2004 volume of a bilingual journal called Feministas Unidas. It was used there is passing, without explanation, apparently assuming the readers were already familiar with it. https://people.wku.edu/inma.pertusa/encuentros/FemUn/newslet...
There are reports of online usage of both "Latinx" and "Latin@" going back to the late '90s. There are other references to academic uses that I haven't been able to track to original sources after a brief search.
Mainstream media (in English or Spanish) only appears to have discovered it in the last few years. I do get the impression that a lot of early adoption was from English-speaking Latinos in the US, which might explain the apparent incompatibility with actual Spanish. I don't read Spanish myself, so there's only so far I can pursue this. But it's not a recent invention of clueless white people.
On “Latine”: at a recent gathering of friends I mistakenly said «miembre» for “member” instead of «miembro» (I’m still learning Spanish). This led to a certain amount of hilarity and jokes aimed at the progressive gender-neutralizing crowd, that likes to use «e» endings instead of the correct ones. It’s a small extremist minority, and a general butt of jokes here. So «Latine» would be seen as just as ridiculous as «Latinx».
"Latinx" is a germanic language construction grafted onto a Latin-based word. It makes no sense, and is non-pronounceable in Spanish. "Latine" is, perhaps, pronounceable, but is a confusing suffix. My recommendation is to drop this silliness. Germanic languages (English is one) and Romantic languages (like Spanish, French etc) have rules and trying to bleed rules from one into the other leads to the hilarity that you describe in your comment.
(I speak conversational German, a little Spanish, native English)
There are reports of online usage of both "Latinx" and "Latin@" going back to the late '90s. There are other references to academic uses that I haven't been able to track to original sources after a brief search.
Mainstream media (in English or Spanish) only appears to have discovered it in the last few years. I do get the impression that a lot of early adoption was from English-speaking Latinos in the US, which might explain the apparent incompatibility with actual Spanish. I don't read Spanish myself, so there's only so far I can pursue this. But it's not a recent invention of clueless white people.
"Latine" is a compromise I've seen proposed recently. https://callmelatine.wordpress.com/