Next time that happens to a thread, could you let it go without talking about it for 8 more posts? I read all that you know.
If I recall, the term 1337 comes from a shortened form of "elite" or "elitespeak", meaning, it was an attempt at inventing a code that you can only decipher if you know how it works and outsiders are left out. Hence they are not part of the elite. Except the code is to use other symbols and make them resemble letters and the whole thing was practically pointless, except for of course getting past bad word filters.
I think the only time I've ever seen it was when it was used ironically or comically, except even then it is rarely in the original form or it looks more like texting-speak so that hardly counts.
In other words, it's dumb, it only shows up when people are making fun of it, and even then they probably aren't using the pure form because that's ridiculous.