There have been 30% stock price drops multiple times during the 13 years of continuous growth. They are clearly not correlated with the actual growth prospects, and if the stock market actually thought that Apple was dropping like a rock as you claim, you would expect to see a far higher discounting.
You mention the Mac, which as declined in absolute terms but has continued to grow relative to the declining market.
The same is true of the iPad, and there is evidence that it's decline is actually halting - I.e. it is reaching a plateau that is lower than its peak. Whether it will return to growth or not is an open question, but it is clearly not dropping like a rock.
So - the stock market story doesn't support your conclusion, nor does the iPad or Mac.
That leaves the iPhone. It is possible that the iPhone has reached a peak in terms of revenue.
Is it possible that it has reached an all time high in terms of active user base? That seems extremely unlikely.
For one thing, the total number of iPhones sold per year is still astronomical, and the devices have a long useful life. Even without a change of strategy, there will still be a huge number of new iPhone customers over the coming years.
Secondly there are many possible strategic solutions to a reduction in sales. Apple is selling far more SE devices than they anticipated, suggesting that there is pent-up demand for cheaper iPhones. They can address this segment easily, which will continue to increase the user base of IOS, even if revenue growth stagnates as a result of lower ASPs. This is just one possible strategy adjustment that would address the concern.
As I said, there has been a decline, but nothing supports your conclusion that Apple is 'dropping like a rock'. As such this is a bad conclusion on which to make a choice about whether to learn Swift or not.
This "dropping like a rock" quarter was Apple's third most profitable Q2 of all time and they made more money than Alphabet, Microsoft, and Facebook combined. The Apple Watch so-called "flop" is estimated to have outsold Rolex by $1.5 billion in the past 12 months. Their services revenue grew by 20% year-on-year.
At some point you have to realise that there's nothing Apple can do that would count as a success in some people's eyes. They are the most successful total failure I've ever heard of.
Your message isn't really that convincing. Apple, while it may be "dropping", is far from doing so "like a rock" – the platform is clearly huge and will very obviously continue to be so for quite some time. Added to that, Swift is not an Apple-only technology.
Perhaps Swift likes Actionscript? That's where a lot of professional left Actionscript for Scala and some invested and adopted Swift. Who cares about sales drop when it's not your job, when the main goals to get Swift on cross-platforms and IoT. Contents drive sales, you seen Windows and BB, Jolla phones have failed.
It's safe to predict Swift will supported in Android and I still prefer iOS for entertainment whereas I have a bad experience on many Android phones for years including it took years for Samsung and LG to release new ROM.
You mention the Mac, which as declined in absolute terms but has continued to grow relative to the declining market.
The same is true of the iPad, and there is evidence that it's decline is actually halting - I.e. it is reaching a plateau that is lower than its peak. Whether it will return to growth or not is an open question, but it is clearly not dropping like a rock.
So - the stock market story doesn't support your conclusion, nor does the iPad or Mac.
That leaves the iPhone. It is possible that the iPhone has reached a peak in terms of revenue.
Is it possible that it has reached an all time high in terms of active user base? That seems extremely unlikely.
For one thing, the total number of iPhones sold per year is still astronomical, and the devices have a long useful life. Even without a change of strategy, there will still be a huge number of new iPhone customers over the coming years.
Secondly there are many possible strategic solutions to a reduction in sales. Apple is selling far more SE devices than they anticipated, suggesting that there is pent-up demand for cheaper iPhones. They can address this segment easily, which will continue to increase the user base of IOS, even if revenue growth stagnates as a result of lower ASPs. This is just one possible strategy adjustment that would address the concern.
As I said, there has been a decline, but nothing supports your conclusion that Apple is 'dropping like a rock'. As such this is a bad conclusion on which to make a choice about whether to learn Swift or not.