Apple - How to Uninstall Qt in El Capitan?
New location of Qt folders is at
/Users/Masi/Qt where you can find
SDKMaintenanceTool which you just double click and select uninstall all components. Source here.
When I have to uninstall apps on a Mac, there is a utility that was reccomended by Macworld.com that has been an indespensible tool in my Mac toolbox: FreeMacSoft's AppCleaner
It has a super easy to use Drag-n-Drop interface or (my preference) you can search for the App you want to delete with their search function.
The tool also deletes all of the other files that the application creates but are not located in the application folder (like Launch Daemons)
This free app has been indispensable to me for keeping my system tidy when I remove unwanted applications.