> What sucks about PrintScreen (or Alt+PrintScreen)?
In which desktop environment? Gnome? KDE? This is not an universal shortcut in X11 or Linux in general. Instead, your environment has PrintScreen configured to launch some screenshot application which comes with the environment. Maim is an alternative to that tool.
Similarly, you can configure Xhotkeys or your desktop to launch main or scrot or GraphicsMagick's import under any desktop environment or window manager.
Yes, that would be gnome-screenshot then. This application as well as the default keybinding are specific to Gnome. gnome-screenshot is alright for the task, but OP's maim tool has some more features and it does not depend on Gnome.
Lots of people who run Linux do not use fully featured desktop environments with bells and whistles but prefer a lean and mean windowing environment instead.
In which desktop environment? Gnome? KDE? This is not an universal shortcut in X11 or Linux in general. Instead, your environment has PrintScreen configured to launch some screenshot application which comes with the environment. Maim is an alternative to that tool.
Similarly, you can configure Xhotkeys or your desktop to launch main or scrot or GraphicsMagick's import under any desktop environment or window manager.