Agreed. Apple is doing something wrong.
Every new OS X version has broken software, and most software companies took the opportunity to charge for "upgrades" that "fixed" the compatibility with the latest OS X release. That definitely is something that's wrong in Apple's OS X ecosystem.
Now El Capitan initiated the same cycle again. Neither Microsoft Office 2011 nor Office 2016 work properly with El Capitan - Outlook hangs immediately when it starts synchronizing with an Exchange Server and hence has become entirely unusable on El Capitan. It's Apple's job to make sure that applications like Microsoft Office still run on the latest OS - not Microsoft's. After all, Microsoft didn't change their code base, but Apple did. Since this happens with every new version of OS X, it's rather obvious how much Apple sucks at providing backwards compatibility.
Even VMware Fusion 8 Pro - which supposedly was built for El Capitan - crashes on certain operations like resizing the vdisk of a VM. Yes, this could be VMware's fault. Or it could be caused by changes made by Apple between beta drops. The only thing that matters is the instability of Fusion on El Capitan.
The third thing that I found was that a driver for a USB Ethernet adapter that was explicitly designed for El Capitan simply didn't work with the GM candidate. (Well, let's no longer call it GM candidate, because it should be very safe to assume that this built will come pre-installed on the next Macs.)
Those three things alone render El Capitan useless for me, because I need them in my work environment.
I also went through Microsoft's Windows 10 beta program, and while none of the betas were overwhelmingly stable, the 10240 build that turned out to be the "real thing", worked extremely well and I ran into no showstopping issues with it at all. Neither were there showstopping issues with Windows 8.1, 8, 7 or even Vista before that.