Only the first netbook came with Linux. The Asus EEEPC 701. This was mainly because it was so underpowered it couldn't run windows (and some nonresizable dialogue boxes didn't even fit on screen). But they dropped it with later models.
I can imagine also because Asus' distro was pretty terrible, it probably gave some backlash against Linux. I think the only reason they made it was to make it work on that tiny screen.
I spent ages at the time trying to make macOS work. I had it booting but due to the CPU being below 1 Ghz the timing screwed up and timing related actions happened in slow motion (this was a timing divider issue not sure to the slowness itself). I even messed with the kernel code trying to get it to work.
On a later Acer netbook I got it running perfectly though.
It was rather limited though, in the amount of applications running simultaneously, around four if not mistaken, without going into press archeology.