1. Panels are fixed in place and don't have title bars etc. They're the only window type like that so you'd have to go to extra effort to make a UI to "lock" windows and unlock them or whatever.
2. If you delete the launcher then how do users start apps? Some old DEs let you right click the desktop but that's not very discoverable.
Much easier just to have settings somewhere do let you say which side (if any) you want panels on.
Comments
I guess there are a couple of issues with that:
1. Panels are fixed in place and don't have title bars etc. They're the only window type like that so you'd have to go to extra effort to make a UI to "lock" windows and unlock them or whatever.
2. If you delete the launcher then how do users start apps? Some old DEs let you right click the desktop but that's not very discoverable.
Much easier just to have settings somewhere do let you say which side (if any) you want panels on.
You can delete the launcher on most DEs. I do not have a launcher button on my work KDE desktop - I start apps using the keyboard to start a launcher.