It's not that people enjoy salsa so much more than other dances, but they enjoy it more now. Dances are often fads, and right now we're in a salsa fad (the tail end of one, I believe, but that remains to be seen). A dance fad may be kicked off by any number of factors: being prominent featured in a movie, a band that plays that style may be kicked off, or an underground movement explosion, are some of the most prominent. The end result is that a lot of people who'd previously rejected dance are exposed to a new dance.
Because the dance is new, it doesn't carry the same baggage and associations that follow classic ballroom and Latin dancing. Although a salsa club and a studio's Latin party will feature the same music and the same dancing, they go by very different social rules, and many people will be more familiar with the club or appreciate its other amenities (such as alcohol). Furthermore, because people are aware that the fad is new, they often feel that it is more acceptable to be a beginner. Because the fad dance is seen as part of popular culture rather than dance culture, it is a more accepted tool to meet people for romantic or sexual pursuits. All of these combine to make the fad dance seem more appealing and acceptable to the dancing public than classic ballroom or Latin.
Note, however, that fad dances are not limited to salsa. Before salsa there was a huge swing fad, and before swing there was hustle. Tango goes through a resurgence every few years, usually in conjunction with a movie reminding the public about its existence.
