: Of course, but if they don't ever need to be online at all , you can't
: guarantee cool stuff like Forza 5's driver dynamic will happen, for
: example. If you can't guarantee it, why even waste time, effort and disk
: space developing it?

Because core functionality of games with features like that didn't hinge on the presence of those features anyway. They can still develop them, and connected players can still use them. Just as it's always been.

And it's not like your online audience is going to vanish just because the console is usable by non-connected people; your userbase for the online feature is probably going to be just as big, and thus just as worth developing.