I don't think regular linux users realise the importance of a good UI to make linux go mainstream and be accessible. No UI for the firewall, no UI for scheduled jobs (CRON), no UI to give the right permissions to enable some script to execute. Lots of acronym based commands that are anything but intuitive.
As is, my experience of linux is that it is a "RTFM or die" system.
[edit] and also the python 2 vs python 3 thing, which technically isn't linux's fault but that I wouldn't have to deal with if I could use .net. This was my first experience with python and I lost two hours on a bug to realise that python 2 wasn't compatible with SNI. And then you have several versions of python installed and to run anything you have to specify the right version and sub-version of python in the command. This was an awful experience.