usability: why try to hide the suspend button in GNOME?

Background: Where is the suspend / hibernate button in GNOME Shell?

I think this design looks clean and convenient to use, but virtually impossible to discover without the help of Google. It seems that developers are deliberately discouraging the use of sleep.

  1. There is a lot of space in the drop-down menu, so why not add another sleep button?
  2. After pressing the shutdown button, a pop-up message appears allowing the user to select between restarting and shutting down, which is a classic design that dates back to Windows 9x, so why not add a sleep or hibernate option?

Is there an email thread that can explain the justification of the current design?