I'm one of those people who upgraded to Yosemite in an attempt to fix this. Well, that was one reason. The other was I like shiny new bells and whistles.
As to the question of why I would do this in an attempt to fix the wifi syncing problem, it's pretty much from desperation. I had a choice, leave it for weeks before the problem is fixed, try to revert back to iOS 7 or upgrade. The upgrade, while clearly not the solution in the end, was the easiest of those choices.
I'm not a tech person but my thinking was that clearly iOS 8 and Mavericks have a problem talking to each other. There is definitely a problem introduced by iOS 8. So, maybe, just maybe, since they were released at almost the exact same time, iOS 8 and Yosemite would not have that problem.
Yes, I still don't have wifi syncing but I do have shiny bells and whistles (and their own sets of new problems).