I'm not sure where you're going with this, but it's digressed far from what I was talking about. To paraphrase your argument, you're talking about assuming convexity, which is a big deal in financial modeling.
If convexity isn't assumed, you're right back to my original point.
Algorithmics would disagree with you: the greedy algorithm, or trying to find a global maximum from local maxima, usually fails as a method. It's usually a "stupider" way of doing things :P
My own experiences, especially related to corporations, seem to corroborate this.
> but is $9/worker/month really a lot to pay for all the stuff GitHub offers?
You make it sound like they're curing cancer. What does GitHub really offer above and beyond the other providers?
As an example, their PR reviewing systems sucks balls. It chokes on larger PRs (250 files!? Really?). Also, with files which have been essentially replaced, the diff can become so large that GitHub won't even show it, and since you can only add comments on PRs, you're sunk. I have to resort to sending around emails with code lines and comments on them.
GitHub is amateur hour. Their half-assed implementations of almost every piece of their functionality reminds me of the same BS Apple does on iOS.