With services like Apple Pay, Apple Music, new products like the Watch and rumored future products like a Tesla-esque car, I'm starting to think that Apple is drunk on power and trying to do too much
10 years ago, Apple were selling iPods hand over fist. Why not stick at what they were good at rather than try and diversify into phones? The first attempt was so much of a flop that you probably don't remember it (a joint venture with Motorola to put iTunes on a phone). ANS: because people were already starting to use their phones for music and if Apple hadn't got into phones they'd have seen the iPod market evaporate.
Now, the PC market is stagnant: you might want to blame mobile devices, the failure of Windows 8 etc. but a major factor is that the PC has matured: you don't
need a new one every 18 months when your 5-year-old MacBook Pro is still a very nice machine that will do everything up to and including editing high-def video.
The phone market is also at saturation and, likewise, there isn't anything really wrong with your 3-year old phone (be it iPhone or Samsung Galaxy). I'd certainly not consider another 18 month contract-subsidised phone (I did the math last time round and as soon as you keep your phone for more than 2 years contracts cease to make sense). The iPhone has many credible competitors and Apple will have their work cut out to maintain their market share.
Ditto tablets - I suspect that we've passed 'peak tablet' and that the traditional iPad-sized tablet will gradually be squeezed out by phablets and cheap 'media cosumption' devices at one end and ultra thin/light laptops at the other.
Apple can't bank on phone, tablet and Mac sales continuing unabated and while can
try to drive sales by innovation there's a risk of 'if it ain't broke don't fix it' (See: Windows 8 and, to a lesser extent, OS X post Snow Leopard).
So the watch and the car are quite prudent attempts to diversify. When someone gets the smartwatch formula right, they'll have a cash cow for 5 years. If electric and/or self-driving cars take off, again, there will be 5 to 10 years of huge sales.
I doubt the $20k watch has caused Apple any loss - I suspect its main purpose was product placement (which goes on the advertising budget) and anybody sufficiently rich and vacuous to actually pay $20k for a gold copy of a mass-produced watch is just a bonus. (If I paid $20K for a watch I'd want to get something actually distinctive which didn't need a professional assayer to distinguish it from something costing $400).
As for the car, we still don't know whether Apple will actually produce a car or just design electronics and UIs for other car makers: the ergonomics of most cars, even quite posh ones, is rubbish and I can easily see Apple-branded entertainment and navigation systems as an option on mid-range cars.