Ah, yes, "that's perfectly good asphalt" so let's keep it. On a grand scale it does seem to be cheaper to leave such patches, but in the end it's easier to erode and break again and it never looks new. However, don't be surprised if a few years from now that patch is still there and they're redoing the new parts. Often things built 50 years ago are more likely to last 50 more, that those from 5 years ago are likely to last 5 more without repairs. They reasphalted my street a couple of years ago. Now it has at least one tiny sinkhole.