It's a bit disingenuous to say that budget airlines 'tend to skip' optional items. If it had been clear that this is actually an important item, I would have expected someone like Boeing to say "this is important, it is a required item, not optional".
Optional is "nice to have", not "oh, this is important!" - It's more like Boeing is happy to charge people more for things that should be there, kind of like the bad Ryanair joke of charging for the oxygen masks.
Biting the hand that feeds IT
