The term ‘elite’ originated from old school gamers in the early-to-mid 90s on internet game servers. Someone who was ‘elite’ was a particularly talented or highly-ranked gamer, and was looked up to… usually someone who had been playing the game or frequenting the server for a long time. Leet speak was usually only used by these ‘elite’ people who regularly frequented the server, and newcomers (or the ‘n00b5’) didn’t know what it was. So it was eventually referred to as ‘elite speak’, or the language used by the elite ones. And as you now know it was eventually shortened to leetspeak, or |3375P34|<.
As an aged hacker (not cracker), perhaps I can enlighten some people.
‘leet’ or ‘1337’ or ‘L33T’ or any number of variants come not from ‘elite’ hackers, at least not in the way that you think.
There was once a group of crackers and hackers way back called “Elite” or “Elite Group”. Their exploits resulted in a little fame, so people started looking them up in search engines. In order to hide a slight bit from the search engines (and be cool, well before script kiddies made it uncool), they changed ‘hacker’ to things like ‘h4ck3r’. And ‘Elite’ became ‘Leet’ became ‘1337’.
For a good while script kiddies claimed they were ‘leet’, and part of the Elite group. That’s (IMO) when things went to hell in a handbasket.