The ironic thing is that Linus started work on what became Linux because he could not afford to buy a Unix license for his PC. Twenty four years later and Linux is well established on servers and mobile phones, and pretty much owns the super computer space, but is still around 1% use on desktop systems. Things seldom work out as envisioned!
Linux users love to claim the android market.
Linux doesn't run on cell phones, a proprietary derivative of it does.
The same with the tablet market.
I wish Linus had had the insight to base his kernel on more modern concepts than UNIX.
Linux has just become another monolithic beast.
As to large firms using it, why wouldn't they adopt free UNIX?
As to individuals being asked to us an OS with UNIX roots?
Personally, I find BSD based OSX to be far easier to work with.