I am shaking my fist at Apple! I understand the issues with software development, having run a large organization that used 3rd party tools as well as Apple's, Microsoft's etc. I personally have several projects that all run on 10.5 to 10.10. This is not hard to accomplish. Code signing is relatively simple, and Apple actually provides the tools and instructions to support signing app bundles linked from other development environments.
It upsets me that decisions are made based on perception rather than facts (not many people still using 10.6.8). Wall Street can't drive your business, just like it can't drive your customer's requirement of a quality product that lasts more than a year. Remember, customers are the ultimate goal, not earnings for shareholders. Apple and other US corporations need to learn that lesson from another friend of mine, Dr. Amar Bose, who intentionally kept his company private to insulate his staff from the illogical motives of financial analysts that know nothing about your business, and even less about being successful over the long term.
Apple's recent OS releases are a mess! The number of significant defects (I did not say bugs) is increasing, mainly because they don't have time to allow maturity via actual deployment. Apple has adopted the Bill Gates philosophy of we may not ship a perfect product, but we will ship first, and grab that market share. That works for a while, but look at Microsoft today, after both Gates' and Balmer's missteps, i.e., Windows ME, Windows Vista, now Windows 8. Microsoft has missed significant opportunities in 8 out of the last 14 years based on the mentality now being employed at Apple.
I knew Steve Jobs personally for well over 20 years. He would be taking significant action after the slack roll-out of Mavericks, and the recent defective iOS 8.x right out of the box launch!
Testing modern operating systems and application is complicated, and a limited beta group cannot sort out the possible defects in an OS that's deployed to millions over a period of several short months.
Don't get me wrong, I am a strong advocate for Mac OS on UNIX. In fact, I was the one that initially approached Jobs while still at NeXT, asking him to consider a port that would run on Motorola architecture, in a Mac. After his return to Apple, I let him know how important it was to the enterprise that Macs get an OS with real security, and built in management capabilities. Yes, that was the beginning of the UNIX - Mach kernel on Macs, and the end of Motorola processors, for reasons that shall remain private.
In conclusion, to quote an overused cliche, be careful not to throw the baby out with the bath water. The problem here is there was no bad (mature legacy OS's like 10.6.8), as the good is the UNIX - Mach underpinning of Mac OS, while the bad is becoming the further closing of Apple's source and forsaking almost all backwards compatibility for the modern OS.