Not sure what you mean by this. I can download and run older versions of OS X from the App Store and install them, or go all the way back to Snow Leopard on my System Installation Disc.
Agreed, I'm running pretty much 3 OS's on both of my Mac Pros: snow leopard, mavericks and el capitan. But you know, that's just being able to plug in 4 hard drives into the old Mac Pro...
Well, I don't mean to invalidate your experience, but more than 8 years of service out of a laptop seems pretty good. Sorry to hear about your 10.9 woes, I had a similarly frustrating experience when I updated my early '07 iMac to Lion.
But for perspective: I doubt a Windows laptop from 2007/2008 would run Windows 10 comfortably! Matter of fact, I have a generic '09 Asus laptop and it struggles even with Windows 7 (it came with Vista and that was even worse). It did run Ubuntu 11 and 12 pretty well for a while, though.
As a rule, I usually make a backup of a fine running system before I update the OS, so I can always revert if things aren't working well.
Good luck!
I also think that Apple's software to hardware backward compatibility is still great, reliable and unprecedentet but still, the OS is getting progressively worse with every release.