You're making a big assumption, which is that the OP even speaks English. He's seeking to have a discussion, not reinvent the wheel, and I don't think he's done anything wrong by posting in his native language. As you can see, he's got several responses, so it's relevant in terms of the fact that on an international forum, we will have hundreds if not thousands of Spanish-speaking members.

I broadly agree that where there is a free choice, English would gain a wider audience, and indeed an earlier poster has said as much. Where it is not a free choice, I would rather have well written Spanish than machine translation. However, I have understood useful technical information from forum posts and documents in languages that I do not speak (Italian, German, & French) and am grateful to the original contributors for posting them. The purpose, after all, is communication.

Seriously, if we get an enquiry in Hebrew from someone who doesn't have a better option, I hope you'll respond - in Hebrew. Also keep in mind that some countries teach substantially in English by default, some don't, so what's "normal" to you might not be in Argentina.