Because the iPad isn't the problem.
The entire tablet market -- iOS, Android, Fire OS, and Windows -- is stagnant, and it has been so for more than a year. That should surprise no one. Tablets sold like hotcakes for the previous three years, and in that time, pretty much anyone who wanted or needed a tablet got one. The opportunity for continued hypergrowth is simply over.
The purported large-screen "iPad Pro" that rumors say Apple will announce in September won't help iPad sales appreciably, if at all. First, this is a perennial rumor, so it's as likely to be untrue this year as it has been the last two years.
Even if it is true, so what Reacting to "iPad Pro" rumors, Samsung came out with such a tablet a couple years ago, the terrible Galaxy Note Pro 12. The multiwindow software didn't work well, killing that supposed advantage of a large screen.
But the real problem with the Note Pro 12 was that it was too big to handle. You had to use it at a desk, at which point a laptop makes a lot more sense.
I believe Apple already knows this, which is why it came out with the MacBook 12 earlier this year. It's a lightweight MacBook -- lighter than the MacBook Air -- meant to be used as a supplemental computer much as people expect the "iPad Pro" to be used. In other words, the MacBook 12 is for all intents and purposes an "iPad Pro."
An iPad makes sense as a device less than a laptop and more than a smartphone. (Yes, larger smartphones like the Samsung Galaxy Note 4 and Apple iPhone 6 Plus have encroached into some of the tablet's sweet spot, reducing many people's need for tablets.)
Maybe there will be an "iPad Pro" and it will do something unexpected and compelling that will create a new niche in the mobile world, in the way Apple is trying to do with the Apple Watch. I accept the possibility. But I wouldn't count on it.
Tablets, especially iPads, are like laptops in that models perform adequately for years. The truth is that a nearly four-year-old third-generation iPad is still a perfectly good iPad, and the advantages of the newer generations (speed, weight, and Touch ID) are simply not enough to justify spending $500 to $1,000. Just as people hang onto PCs for years because they run perfectly fine, so too do they hang onto iPads.
Most tablets sold are used as media tablets, meaning they're used as e-readers, video players, and Web surfers. That's even more true in the Android and Fire OS worlds (Fire OS is the Kindle Fire's operating system) than it is in the iPad world, so it's no surprise that those tablet markets aren't in hypergrowth either.
Across the board, tablets are in a replacement-market phase, and that will tamp down the demand for the foreseeable future.
Windows tablets may have shown a burst of adoption this spring -- their market share doubled to 6.6 percent, according to one (and only one) market survey -- but even if true, that's misleading. When you have a small base, it's easy to show growth, especially in a market that has flattened and where small changes are more visible in the data. But the total numbers are tiny -- and have been since the first Windows tablet debuted in 2002. Plus, Windows tablets aren't really used as tablets, but as laptops with a detachable keyboard. They should be counted as PCs, a market where overall sales continue to decline.
The growth all of the above leaves for real tablets is the kind of normal growth people should expect, which is what Forrester Research, among others, predicts. The problem is one of expectations, no more than that. Sure, Apple, Samsung, and every other vendor wants to be the hypergrowth exception, as do their stockholders. Although they should try to do something compelling to move the needle, we shouldn't expect that it will happen. Disruptive innovation doesn't work on a schedule, and it isn't a perpetual-motion machine.
The good news is that corporate sales are steady, so iPads are becoming part of the standard computing mix. That means they'll have a long-term future because companies keep investing in their core technologies. Consumer fads won't easily shake that IT investment approach. It took years for businesses to take iPads seriously, and it will now take them years to stop doing so.
I am glad to see enterprises finally wake up to the realization that an iPad is a serious computing device in its own right, different from a laptop, even though there's overlap. (iOS 9 will make the iPad's laptop-ness even more apparent.)