True. For simple overlays, I don't go that far, and I only use the parts that are needed to achieve my end. In your case, it sounds like you only need the tool tip part.
To understand why I do it the way it's outlined in the tutorial, take note that in a GUI without without a glass pane, a tool tip will disappear when the mouse leaves the respective component, and the delay to reshow the tool tip will start over when the mouse enters the bounds of the next component. The problem with a glass pane that is rendering tool tips for underlying components is that the tool tip text doesn't automatically disappear when moving from one underlying component to another. Once the overlay's tool tip appears, moving from one underlying component to the next will change the tooltip text but will not hide the popup. I find this annoying—especially if the underlying component is something informationally dense like a table.
I address this issue in my tutorial by tracking the underlying component path and manipulating the tool tip timers when the underlying component changes to produce the natural expected effect, but if you don't care about hiding the tool tip popup and reinitializing the delay time between components, that script could be greatly simplified.