It is not uncommon for us to pull elements from other dance styles to create our own routines, in fact,this has been a long tradition in the evolutionary history of dance to share figures (click here for Dance History at a Glance, or here for Dances' History Intertwined for more). Through so many years of 'sharing', our dances now look the same- if you mute the music, you can't tell whether a couple is dancing Salsa or Samba, ChaCha or Rumba.
Is it inevitable that the individuality becomes blur? Maybe not.
Certainly we gave the same figure in a number of dances, for instance, the very popular figure, chasse, is in Jive, Cha Cha Cha, Waltz, Quick Step, Paso Doble, but when it is executed, the dance never looks alike (read here for the Chasse in different dances) because first, the music which defines the dance has significant difference; second, the dancers are alert of the personalities of the dance.
People who see dancing is just a series of steps may be able to dance a number of dances styles, but they do not identify the characters of each dance. We give each dance style a name because even they all evolue from the same one source, i. e. Mambo, each descendant has its own style!
Personally, I think keeping and retaining the difference is important. Not only because it is the key to win in a competition, but also because of the cultural value. We pull the figures and share the steps because we want to enrich the world of dancing; if we lose the dances and merge them all into one, we are actually achieve the opposite.
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