Apple has really pushed the bar up in terms of what users expect from their computers out of the box, and that has affected Windows as well, so in some sense Linux has been swimming upstream? treading water?
In the mid-90s I remember endlessly fiddling with CONFIG.SYS and AUTOEXEC.BAT to squeeze out that extra 30kb of conventional memory to run some game. Buying peripherals was such a crap shoot that 'Plug and Play' was something that needed to be advertised, and much of the time you were still stuck manually juggling IRQs, moving cards to different slots, etc.
Nowadays, one can buy any Windows or Mac computer/peripheral and generally expect it to work, with some bare minimum of reading reviews.
So while Linux has made tremendous strides in terms of driver support (you mean my wifi actually works now?), things are still very far from zero conf that users have become accustomed to.
Time is valuable, and 2-10 hours spent experimenting with various driver packages, editing text config files, recompiling the kernel, etc. is literally money out of the user's pocket, not to mention the learning curve if you don't already know how to do all these things. That doesn't include the time for extra research to see what hardware is well supported.
Here's an example of install instructions on a pretty well-supported laptop that does Linux [1]. I'd guesstimate an hour of time if you've already done this before, and anything up to 10 hours if you run into unexpected difficulties or are totally new to this.
[1] http://chaos-reins.com/2016-11-14-arch-yoga-910/