Please stop moving goalposts. Either Linux is successful, or it isn't. Android proves that it is successful on cellphones (which likely means it's the most used Operating System in the whole planet).
It's is successful in server applications. It is successful in cars. Consumer devices. And so on.
Just because you don't see many people doing their Excel spreadsheets on their Linux PCs doesn't mean it is not successful.
Also, Linux started with NO business model. It started out as a "fun" project – and because the Unix operating systems at the time _had_ a business model, which made them cost prohibitive for many people.
I think we need to re-examine the playing field here.
Correct me if I'm wrong but Haiku appears aimed strictly at the desktop as a general purpose OS.
Cellphones, servers and embedded systems are all out of it's league --- and thus the success of Linux in these areas is not really relevant to the topic at hand.
Sure, I think people are just objecting to the implication that Linux as an OS had a 'business model' or 'commercialization' problem; in the very early days (I was there) this was the case ... except it was all mostly being done for fun. But these days... it's just everywhere. It's the lingua franca OS for almost all hardware, for better or for worse.
And it certainly wasn't targeted originally for cell phones, etc. And it arguably isn't best suited for it. The unix perimission and user model and file system structure etc make little sense there. But somehow it ended up there.
Arguably a finely tuned single user system makes more sense for those types of system. so who knows... maybe Haiku or something like it has a future there. I doubt it, as I think of Haiku more of a lovely retro computing project... but it's somewhat conceivable.
I mean... former Be engineer Travis Geiselbrecht was behind the early days of Haiku and he's now key behind Fuchsia. So there's some cross polination into that kind of ecosystem anyways.
Again, not what Haiku is about.