Well, there’s a plethora of screenshot tools like Kazam, Shutter and Flameshot to mention a few, and people tend to use their own favourite.
Hence there are going to be a lot of people uninstalling and then installing what they want. It didn’t take that long to install Spectacle, right? 
KDE Plasma has a rep of being overly bloated, so I personally think it’s a good thing to keep it as lean as possible.