I agree about Steve, but he must have realized without himself in the picture, Apple would need an alternative plan to continue to exist. Steve used to refer to Tim's ability to keep Apple afloat... certainly he wasn't referring to Tim's technical acumen.
I think Steve also understood that major technological shifts/breakthroughs don't happen very often. There are decades in between. Apple needs someone with Tim's skills to lead them at this point. Yes, Tim is all about the money and that's a good thing. It means the 90s can never happen again. The question is, when the next major shift happens, will Apple lead? I rather doubt it, just as no one expected Apple to lead the mobile revolution. But obviously the hope is that, yes, Apple will one day come up with the next "next big thing".
The iPhone will continue to be a cash cow for the foreseeable future (70% of revenue) and everything else is basically an iPhone accessory to the company anyway at this point. The entire Mac business could vanish and it would rarely register. We're not going to see daring, innovative upgrades to any Mac ever again. I don't think the new Mac Pros flew off the shelves. Apple wants everyone on a device upgrade cycle. Remember, they make their money selling hardware, not software, so they need people to buy new hardware on a regular basis.
Personally I've been rather bored with Apple and Apple products lately. The watch was utterly predictable and in no way exciting. The new iPhone 6s features are cool, but there's no "wow". Apple TV upgrade was modest and gaming appears rather weak. New Mac hardware...nice, not exciting. Apple Music? Is anyone using it? Apple Pay? Even where supported, hardly used by consumers. iCloud, sigh...
What worries me as a long-time Apple customer and investor is how many negative things I'm hearing about Apple in my peer group. I'm the Apple guy that everyone asks for help. And in the past year or so, I've noticed a real increase in the number of complaints and negative comments my friends and family have about Apple products, user experience, etc. I'm genuinely beginning to worry that Apple is becoming the Microsoft of the 90s.