A common told story is, that many different operating systems are available and the customer can choose between them. Examples for operating systems are Mac OS, Windows 10, iOS or AIX. But are these software products real operating systems? Sure, it's a rhetorical question which asks what the difference is between propriatary firmware which runs only on a specific hardware over a true operating system which runs on different hardware from different manufactorer.
Let us make a simple experiment and we are take the Windows 10 firmware and are trying it to install on a IBM/z system which is the latest mainframe which runs with the power9 cpu. Will it work out of the box? Or let us take the Mac OS X firmware and install it on a Rasberry PI microcontroller, do we see the bootup logo from Apple? Or let us take the Xbox One firmware and install it on an outdated Pentium III PC, can we do it?
Somebody who is bit familiar with the different hardware systems will answer that it's not possible and even the attempt in doing so shows, that we haven't understand what the purpose of Mac OS and the other programs is. And indeed we have interpreted their purpose the wrong way. The idea was, that Windows 10, Mac OS X or the Xbox one Firmware is an operating system and as a result it is able to run on different hardware. We have ignored, that the term operating system doesn't fit to these programs. That means, Windows 10 or the other example were never designed as a standard operating system which makes things easier for the customer, but they were created as a hardware dependent, company dependent firmware which is similar to the AmigaOS useless, if the underlying company is dead.
The interesting fact is, that no commercial operating system is available for the customer. We are living in the 1950s in which the operating system wasn't invented yet and as a weak alternative, each company has it's own firmware which is not documented publicly.
And here comes Linux into the game. Linux is not the best operating system in the world, it's the only operating system. Linux is the only software which is able to run on an x86 PC, on a smartphone, at the IBM /z machine, at the xbox and even on microcontrollers. This is the minimum requirement before a system can call itself operating system. It makes no sense to argue, if Linux is good or bad, because no competitor is available. Let us make the point more clear. We are take on outdated Amiga500 with the Kickstart firmware and compare the AmigaOS with Linux. What is better? The answer is more difficult than it looks at the first impression. The Amiga Kickstart is a classical firmware. It was designed to run on the Amiga device and only on this computer. That means, it is not possible to run normal software on the KickartOS but only games and application which were tailored for the system's need. In contrast, The Linux kernel is a real operating system which acts as a layer between hardware and software.
The question pro or against Linux is a question pro or against an operating system. If the user comes to the conclusion, that a propriatary firmware is everything he needs, than he will argue against Linux. If the user thinks, that he need a layer ontop of the hardware which makes programing easier than he will argue pro Linux. The question which remains open is, if anybody needs an operating system.
It seems, that today's computing market has answered the question with no. Mac Users, Windows users and Xbox gamers doesn't need a high level operating system, instead they are dependend from the hardware specification. The result for this collective ignorance is, that not using an operating system makes software development more costly. The typical Windows application costs around 200 US$, while the normal Xbox game costs 50 US$. The reason is, that the software has to be programmed for the target platform and can't be migrated to other platforms. The situation looks similar to the Betamax videoformat in the 1980s. At this time the customers has paid a lot of money for betamax cassettes and were not able to use the format in a different video player. They didn't even know, that a common standard would make the life easier and the manufactoring company were smart enough to say nothing.