I don't use Ubuntu. It depends on what garbage you add to Linux to make it a slow pig.
If people are concerned with speed, they can load up DSL or another 50 meg distro that can run entire in RAM.
I can't remember the last time my Linux box crashed, but I'm just a end user and not a Dev. A decent OS is going to take time, AROS has taken what, 14 years to get to where it is today? I think C=USA inked the deal with AI this past fall. That's not much time really when you think what has to happen before the first machine can roll off the assembly line.
People have some amazing expectations about what it actually takes to write an OS.
Windows and Mac OS has been developed over decades, by billion dollar corporations. Linux has been developed over decades, with thousands of contributors, including plenty of billion dollar corporations.
That AROS is where is at, is nothing short of amazing, but the notion that it'll swoop in and suddenly get people to buy that instead of windows is futile.