I'm not sure I'm entirely clear on the supposed bug here. If you quit (File > Quit or Control-Q), the IDE should save and restore the sketches you have open, along with their location and position.
I can only speak for myself (using Linux) but I think many (most?) people close their application windows by clicking the window-close buttons or the Alt-F4 hotkey.
The behaviour of the IDE when the user has only a single Sketch open ...
- Quit via Menu or Ctrl-Q -> IDE starts up with restored Sketch-Window
- Quit via Window-Close-Button or AltF4 -> IDE starts up with Blank Sketch
... is confusing. I'd call this a bug
Eberhard