The question remains, why is this any more a problem than people who base their game on, say, armbars from closed guard, or back takes from de la riva, or single legs from half guard? There is no shortage of any of these archetypes i assure you. People always speak of these things in terms of someone on top 'dropping back', when in fact it's greatest utility is when you're already on bottom; indeed, i would say it is likely the most effective way of fighting while on bottom (besides simply escaping and trying to take them down again). And because it is so effective, people need to know it so they have people to practice with so they know how to deal with it too. Backstepping into saddle is a legitimate way to attack DLR or HG anyways.