Cannot maximize a window by simply clicking on the Photoshop CC app icon
I know you specifically asked for a system fix, but I'm going to suggest an alternative.  I can understand your frustration with the issue as I've worked with CS apps too.

With option-clicking ( ⌥ + left click ) the program icon in the dock, you toggle the entire app's windows on or off.  It leaves the current state of all open windows and their current position/size.

The click-and-hold method you're using would seem frustrating.  You can get to that quicker by just right-clicking the icon (or in case of a trackpad, 2-finger click), or you could just use the hotkey control + down ( ⌃↓ ).

To be clear, the command + M combo you're using will minimize just whatever window is focused, and the trick I mentioned earlier will not restore it - you will still have to get that back via either the Window menu or the other methods we've discussed.

Also you aren't referring to actually maximizing windows, but rather restoring them I believe.  Maximizing can occur on windows in Yosemite by option-clicking the '+' "full screen" button on a window.  There should also be a shortcut somewhere.