So it indeed does beg the question, who is in charge? What were they thinking when they tried to get away with putting this in their S-1? Were they really that inept in revenue recognition, or were they trying to pull a fast one on their potential investors? If anything, it really hits against the credibility of the executives.
As has been mentioned many times, the fact that they sold shares for 900MM and then cashed out their initial investors when Groupon was bleeding money speaks volumes about the character of those in charge.
I wouldn't invest a single penny in this company.
Descriptivism lets language evolve. Prescriptivism (people trying to push it back) is part of that evolution. According to your principles, you should just accept it as the way the language evolves.
There's a reason why majority rules isn't always appropriate. It's because often the majority can be wrong. We won't redefine the answer to the Monty Hall problem just because 9/10 people get the wrong answer.
If we're constantly redefining words and meanings, then why have definitions at all?
Having said that, I still prefer to use it correctly.
All linguists are descriptivists.
Coming back to the original point (and not in response to you in particular), using "begging the question" to mean "raising the question" is very common now, and trying to object to that does no one any favours.