At that time, Linux on laptops was an absolutely great choice.
None of your vendors were considered viable - far, far too expensive. However, Linux on x86 laptops at the time was amazing - portable Linux.
So when Apple joined that party, and made the hardware neat, it was an easy switch. Portable, PPC-based, Unix. This was a delightful moment.
Of course, I still have a Linux laptop around, and 20 years later .. I consider moving back to it, 100%. The ride has been good with Apple, but the horizon doesn't look too great ..
Linux has always worked great if you choose your hardware wisely, and for a long time in the 90's it was perfectly viable to put a Linux machine against an SGI, Sun or DEC system as a workstation. Really, Linux had traction even before the 21st century cloud and 'droid reality came along.
For most of the 90's I was using Linux in some capacity, professionally as well as personally.
I also had a Linux laptop (Winbook, Sony, and then Sceptre..) on which I did a lot of development and for which my carefully selected hardware did in fact work, just fine - it was certainly viable as a dev platform, and for us Unix programmers at the time, a small and light Linux laptop was far more preferable to the pizzaboxes that had to be carried in the trunk .. or more, bigger iron that you would stay at the office to use, instead of having at home.
The point is Linux really did okay in the 90's, in terms of providing Unix devs a way of working away from the computer room. I think this is an underappreciated mechanism behind Linux' success over the years .. you could carry Linux with you pretty easily, but this was not the case for Solaris, Irix, etc.
Like the OP, for me the tiBook was a defining moment. A unix laptop, and it also looked good? Easy, immediate purchase.