"x" is seldomly used in Spanish, and "Latinx" isn't even really pronounceable in Spanish. It's very clearly been created and pushed by people who don't even speak Spanish, so it's perceived as very disingenuous and forced. There are ways to achieve gender neutrality in Spanish in ways that are more fitting to the language, like using "e" ending instead of "a/o", e.g. latino/latina/latine, amigo/amiga/amigue, etc.