Re: TZ
"It is not XFCE's concern. ..."
Rather than installing a new package I use the command line, I chose XFCE for that particular VM because I lacked disk space.
But the real issue is that the IT environment is vast and you can't know everything, especially if you are a developer and not a sysadmin. Yes you can use an external package, but you must be aware of it and if you have to search for a solution you just need once or twice you don't search for additional tools, but for the command line. With KDE you don't waste time searching, you can find the setting in the default widget.
Biting the hand that feeds IT
