Calm down. I'm not asking for a badge of certification whatever whatever. I just don't understand what the complaint is and therefore cannot evaluate it.

[Since you asked, the biggest complaint in my filesystem-centric Windows experience is that filesystem drivers are very "heavy". There is not really a layer like Linux VFS which can handle common bug-prone tasks before they get to your driver. The driver is expected to do a lot. But I don't think drivers are easy on any platform.]