The sand would have to be bloody deep to need a snorkal
I think they are saying the sand particles will block the air filter. So they wish to raise the inlet to stop this from happening. It's commonly known as an excuse for fitting something that they don't need, but regard as looking cool. After all is said and done you can't have a proper off roader without a snorkel and a forty million candle power roof mounted light array can you now?