Last week, Apple released its fourth quarter results. They show that, in that quarter, it sold well over five million Macs, which brought in a revenue of more than seven billion dollars. Far from being the poor relative to the iPhone and iPad, Macs remain a substantial part of its business, revenue, and profits. Not only that, but Mac sales (units) grew 25% over the previous quarter, providing the greatest growth of all its products, both in terms of units and revenue.

Bizarrely, Apple’s CEO Tim Cook didn’t mention the Mac in the quotation given in Apple’s press release. He singled out its services sector, and new products including the iPhone 8 and 8 Plus, Apple Watch Series 3, even Apple TV 4K, and of course the launch of iPhone X. But no mention of the Mac.

He certainly wouldn’t have gone near macOS, and that may reflect one of Apple’s problems. As far as “the world’s most advanced operating system” goes, there isn’t much to crow about.

Just over a year ago, on 20 September 2016, Apple replaced El Capitan 10.11.6 with Sierra. For many Mac users, El Capitan had been a disaster. A brief look at my last and incomplete list of bugs which were left in 10.11.6 makes grim reading.

Sierra seems to have a more stable kernel on most but not all models of Mac, and after the first couple of updates proved robust on this iMac. But other models were notoriously problematic, and my last incomplete list of bugs for 10.12.6 is no better.

Then along came High Sierra on 25 September, just over a month ago. I haven’t even started to draw up a list of bugs, because so few Macs can actually run a full-blown installation, complete with its major feature, Apple’s new file system, APFS. And the second headline feature, new high-efficiency image and video encoding, is even more incomplete.

I’ve lost track of the last time that I could describe a current release of macOS/OS X as being even close to completion.

The model software development cycle consists of a major release with significant new features, following which those features are refined, and bugs are eliminated. This produces a stable and mature product, which is then succeeded by the next major release, with its significant new features.

Because macOS is – quite needlessly – tied together with iOS in an annual cycle determined purely by the marketing calendar, because macOS does not receive the investment which it requires, and because Apple is fundamentally a hardware vendor whose software contributes little or nothing to its revenue, no recent release of macOS/OS X has been allowed to reach ‘marketable quality’. Each has been abandoned, incomplete, and still full of bugs, many of which were present in the previous major release when it too was abandoned.

A case in point is Bluetooth. A fundamental technology on which a whole raft of macOS depends – from wireless headphones to Hand Off connections with iOS – Apple has been unable to provide consistent and reliable connections with its own Bluetooth products, such as its wireless keyboards and trackpads, through El Capitan and Sierra. The same wireless keyboards still stutter multiple characters when not intended to, spontaneously disconnect and reconnect, and worse.

Initial experience with High Sierra suggests that these problems may finally be fixed, but for anyone still using Sierra or El Capitan, there will be no updates and no fixes, apart from security updates. They have been abandoned, like wounded animals, left to die out of sight behind a bush as Apple rushes on with the next major version of macOS, which will doubtless also be abandoned in whatever state it reaches next summer, to make way for macOS 10.14.

Apple needs to step back and think carefully about this annual cycle. It is making it very difficult to use macOS in any production environment, where users need a stable platform to support mature apps which help them do their work.

At present, their best option might be the now-unsupported Sierra, which at least still receives security patches. But heaven help you if you try mixing in High Sierra systems, with their incompatible new file system and, when they are eventually completed, its new image and video formats. And the many bugs that are left in Sierra will remain unaltered, because Apple is only prepared to invest in the newer macOS, rather than support the last major release.

macOS may be free, but without it Apple would lose all those Mac sales, over twenty billion dollars a year of revenue, and more. Doesn’t that justify doing the job properly for once?