Why distinguish between ballroom (Standard for you) and the other dances? One word: applicability.
Although they may have a competitive level, most Latin and club dances can be enjoyed almost anywhere: clubs (duh), parties, dances, etc. They generally don't require a great deal of space and are very popular among all age groups.
Although the popularity of Standard dances may be increasing (debatable), you would be hard-pressed to find any place in the US outside of a studio dance or competition where you could perform them, socially or otherwise. Accordingly, students are restricted in their opportunities to do so. Single students (those without amateur partners) are additionally dependent on their professionals. This dependence makes them subject to abuse.
This situation has no relevance to the dances that you listed because there are generally plenty of partners available. I have heard many women complain about being unable to find partners for Waltz, Quickstep, etc., but I have NEVER heard ANYONE fret about not having a partner for salsa or any other club dance.
jj