Ask HN: If you were to start Linux from scratch, what would you do differently?

It surely is just me, but I have noticed several people in the HN community and others openly complaining about the Linux kernel, and mainstream operating systems in general. I'm sure that, along the way, decisions were made and trade-offs had to be faced, and that resulted in the operating systems we have today.

What, in your opinion, do you think are the decisions that, in retrospective, should have been made differently? Like, for instance, is the concept of File the right abstraction? Is the use of bitwise to assign permissions in files the right one?

I'm looking forward to your answers.