Thats a common response, tho inaccurate. If trained correctly, no single beat is more difficult than any other.Does "1" come easier to most?. probably .But to me , thats a " cop" out .
I do teach both, primarily so that, the ladies are equipped ,for most dance occasions .
Training ones " ear ", as we do in all dances ( or should ) resolves most timing issues.
Heres why the "2" is important, in the Salsa/Mambo genre.. it is built around the Clave And, there are mostly songs that ,are clave driven ( I also DJ and have a very large library ).
Heres a comparison.. knowing the difference between R and R and Jazz, the same is true for the " Rumba " genre.. discerning the differences between a Guajira and a Cha Cha or a Son Montuno from a Montuno.
Knowing HOW and WHERE the "stresses" in the music are, gives us the opportunity to improvise, and the style of music ,normally dictates that.
Salsa is a " Street " dance, and really has little or no boundaries to conform to, other than reflecting the music within the given parameters.
There are numerous other e.g. in the genre .
But, as I stated, there are some songs ( particularly in NY style salsa ) which " feels " more on "1" .Safe to say that, prety much all the NYC salseros, dont entertain any thing, other than "2" .
Going to back in the day ( 50s and 60s ).. ALL studios and dancers in the States, taught and danced on "2", and,most of our clientele ( which was 1 on 1 teaching ,primarily) were ladies 50 yrs and older . Never came across anyone , in my exstensive coaching travels, that had not mastered the "2" in mambo .
In deference to all of that.. I always believe that music and dance, are of a personal choice nature. So, dont let my pedantry obscure that fact .
NB.. in regards of your " hip " motion comment. Yes, it has its place in the genre.. but.. that becomes secondary to other aspects ( frame/hold for e.g. ) AND... the Cuban motion in salsa, is NOT quite the same concept, as in the Intern. styles ( in fact.its completely out of place, and foreign to the style ).