Steve didn't do this. He was a technical idiot and a narcissistic arsehole that gets way too much credit for design and innovation. If anything, he was able to recognize the great product ideas submitted by forgotten minions and competitors and was able to take them to the next level. Only in this respect did his genius and talents shine.
Cook is a boring bean-counter and shouldn't be the "face" of Apple.
Say what you will about Steve. He loved taking a ton of credit and WAS a narcissistic ***hole who was a deadbeat dad and abandoned his pregnant girlfriend, but he was one damn good manager. He regretted his sins and tried to resolve them best he could. And no, he wasn't a technical idiot... he has written code onstage, damn it.
Anyway. I completely agree with you about Aqua and Tiger. Tiger was the stablest, purest expression of what OS X was. No unnecessary crap: just good, easy-to-use software that let you do what you wanted right out of the box. It was fast as hell, and I miss Aqua so much.
I love the refined esthetic of post-Lion releases on Retina Macs; they look extremely clean, but Aqua was so unique. It was Mac's defining feature for over a decade: you saw those Kool-Aid color traffic light titlebarcontrols, and you knew that was a Mac. Instantly. Rounded buttons? OS X. Light titlebar and subtle pinstripes? OS X. Shiny menubar? OS X. Not to mention, the Tiger incarnation was far more pleasant to look at than the fugly 10.2 editions, and maybe a little more pleasant than the Leopard incarnation (which was ironically a bit more shiny in some areas).
I really feel like Steve wouldn't have done much to help the crisis, though... remember, he presided over Lion development, and we know how THAT OS came out.
I feel like towards the end of his life, he became a very bitter, vendetta-carrying man. Okay, we get it, you didn't like Android, but to call it "stolen property" and to promise to "go thermonuclear war" on Google for it when the concept of a GUI was stolen from SRI and Xerox is hypocritical and reeks of a misanthrope.
I do think he would have kept Aqua around in some form or another though. He loved visual cues and despised flat UI design... so I doubt the iOS 7 debacle would have even occurred.
What I do know is that Mountain Lion and Mavericks would have been more consistent. His attention to detail was unparalleled. Say what you will about Lion, but apart from iCal and Address Book, it was one damn consistent operating system.
I still feel like 2009 was the definitive year for Apple. The 3GS, Snow Leopard, unibody Pros, great new iMacs, and iPhone OS 3.0. Nothing short of cohesive and amazing.
4 years later, and the coal is running out. No more steam, I'm afraid... we're running on momentum here. Eventually the train will have to stop... let's just hope it doesn't derail until then.