It's a waste of time look at a bad design and discuss all the ways it could be better. Anybody can do that. Taking an excellent design and finding ways to improve it, now that is interesting. SysV IPC and curses (and device numbers and terminfo/tty and nondeterministic exec and...) have been beaten to death for decades. No need for that on LWN.
Not sure where you see the author saying anything is bad design. He's just considering how good things can be made better. Show me something that can't!