Buying a car is optional. So is choosing whether to drive it to work, or skipping to go play games. Or a lot of other choices that have nada to do with side content in games.
However, if one is driving, and takes their eyes off of the road to look at cut-scenes, could get messy....
Yes, that's my point,
Using a catch-all excuse like "it's optional" is senseless, since buying the game at all is optional.
At what point does any part of any game ever force anyone to do anything?
And at what point does content stop being optional?
One could argue,
A side quest that has any impact/bearing (no matter how small) on main story/characters stops being optional even though it's still a side quest.
Sorry but I don't buy a game, DLC, expansion just to skip content and a side quest is content.
I see what ya did there, pretty humorous.
But back to the topic at hand,
It's a huge leap to say that if there's no CS's= a dev will provide more content in its place.
If a dev was to remove CS's they may replace them with nothing at all.
Anyway,
I still stand by my opinion- it depends.