That makes a lot of sense to me. I'm pretty sure there has been some cutoff like that for as long as their have been utilities.
I don't know exactly how many yards the breakeven point is. However, from what I've seen it is almost always monetarily cheaper to create your own services when possible - unless a neighbor has paid for services to get really close. It might make sense for neighbors to pool money for pulling services out. It all depends on the specifics, right?
I've read recently that as of right now, if you're more than 1000 yards from the branch point the electrical company would run wire from, it is already cheaper to go fully off-grid. Not 100% true that this is true or at least universally applicable, but the curves all point in that direction.