". No one is forcing you to use Mavericks."
Not yet. But isn't it just a matter of time before old OS versions will eventually no longer be compatible with new software and devices (or even new computers) ?
Yeah, for people unfamiliar with the issue, perhaps newer to this forum and aren't interested in reading through 200 pages, this point is really important.
First, there is already software out today that doesn't work on Mac OS X 10.6 Snow Leapard. That is going to accelerate over the next couple years.
Second, and more importantly, there is no going back. Apple did the no-local sync very quietly. Unlike most advancements where they have had good reason to move forward (floppy disks being the go-to punching bag here, with optical drives a more recent example), Apple didn't make a big deal about how iCloud only is superior to iCloud + local sync. Quite the opposite, they didn't publicize the change at all. Searching Apple's web site for syncing makes it seem like, even after Mavericks was released, that you can sync contacts locally. They clearly advertise this feature in their online marketing.
There were no warnings in the upgrade process, and no warnings when connecting iOS devices to Macs for syncing.
So if you did the upgrade, and then a month or two later stumbled across this issue and realized your contacts were no longer syncing in iTunes, you had two bad options. First, you could restore on old backup of Snow Leapard - losing everything you have done since upgrading to Mavericks. Or, you could keep Mavericks, losing the ability to sync locally. When calling Apple Support, their customer reps were told to tell people complaining about this that it's not even a problem!
Of course this forum can't solve that - enough of us have to contact Apple directly for action - but I think it is important to lay out the actual story of what has been happening. The problem is not that local sync doesn't work, or that 'the future' requires abandoning it.