...And yet, in IT, people understand the nature of the problem they're having so poorly that they're very likely to ask that question on Mexico.SE. I don't know how to solve that problem of education without delving into politics and other such controversial topics. But such is the status quo. Don't be one of those people and you'll be fine.
About Your Proposed Cross-Posting Feature
The general idea, as I understand it, is to make it so that you can take a given question and post it once while having it appear on multiple sites. Then:
- The comments made would originate from users of any of the respective sites, and all the comments would be "merged" together.
- The answers added would be merged together, regardless of which site they originated from.
- If the question was off-topic for a site, it'd be clos-- wait, what?
Do you see where this starts to break down? There are a bunch of problems with this that cross-cut the very structure of how Stack Exchange works:
- If the question is deleted, where does it get deleted? Everywhere, or just on the site where the site's users voted to close/delete it?
- If I have a user account on multiple sites and I want to vote to close or delete the question, which site does my vote get registered on?
- Is the question ID for each site different, or the same? If it's the same ID, how do you avoid conflicts across sites?
- If the question is upvoted/downvoted, which site's user gets the reputation change?
More importantly however, why bother having different SE sites if you're going to add a feature like this? Why not just have one gigantic stackoverflow for all technology-related questions?
Well, we already tried that. You don't even need to wonder what the world would be like if you merged all the SE sites into one, because Stack Overflow is so popular that its user community already does that. And there are so many millions of off-topic questions that the users who attempt to improve the site do not have the time and attention span to go through and close all the off-topic and duplicate questions. You can visit Stack Overflow today and see what the "IT soup" site looks like.
In fact, you can probably get away with asking just about any technology-related question on Stack Overflow and, more often than not, it won't ever be closed. That's because SO receives so many questions, and so few users are interested in cleaning up the site, that they can't ever hope to turn back the tide of questions.
So instead of asking for a feature that would make the rest of Stack Exchange just as muddled and crowded with off-topic questions as Stack Overflow, why not just analyze your question a little bit more before you ask it so you know which site to ask it on?
