Re: Business users
"Linux as a file server, but for very simple needs, is really outdated"
clueless. Actually I use FreeBSD, but it's basically the same userland software. It handles my e-mail repo (IMAP), source repository (SVN), and file-based backups and archival storage, as well as internet firewall, internet gateway (PPPoE for a DSL connection), IPv6, DNS server (for a domain), web server, and stores it all using ZFS [the most reliable file system that I'm aware of]. And it does all of that on an older Intel Core Duo running at 1.6Ghz with only 4G of RAM, and I don't have even a REMOTE case of performance issues with it. Good luck getting THAT to work with a windows server, ha ha ha ha ha! And it has Samba running on it for windows shares [all read-only except for a couple - when I want to write to it I use rsync via Cygwin, which is a lot better/safer - in case of a 'wannacry' problem that decides to go after network shares]. And it doesn't expose ports 135-139 nor 443 (by default) to the intarwebs (unlike a windows server).
So, _THAT_ is "outdated"? Hah, I laugh in your general direction!
"Visual Studio is far better than any development solution on Linux, especially those based on vim"
vim? ha ha ha where have YOU been! I prefer using pluma/gedit to VIsual Studio anyway, since visual studio GETS! IN! MY! WAY! most of the time. The last decent MS developer studio was VS98. After that it got all "Visual BASIC" on us, and you have to mousie-clickie-mousie-clickie and move your hand off of the keyboard all the time, especially with the dialog box editor. "property" drop downs, what a freaking joke! I liked the old class wizard dialog-based interface because I had the hot keys memorized and could fill a dialog box with accurately aligned controls in minutes, without wearing my right hand out doing mousie-clickie-mousie-clickie. And that mousie-clickie process SLOWS! ME! DOWN!!
FYI in case you hadn't seen, there are also a couple of other IDEs out there, some written in Java (like Arduino, Eclipse). Eclipse is very popular with Java programmers. It's quite good, actually. It lacks some of the C++ support I'd like to see, but hey, you can't have everything.
Then of course there's Qt, a commercial toolkit. I haven't used it but I hear good things.
"Anyway, developing applications for three platforms would have unbearable costs"
No, it doesn't. wxWidgets. Qt. GTK. All 3 of those are cross-platform toolkits. code to one of them, and it's "good to go".
"especially under Linux w[h]ere very few are willingly to pay, and especially until the desktop gets a unified API" (ha ha ha not a chance) "and a single decent widget set, not that mess Gnome and KDE are."
Gnome and KDE might be 'a mess'. but 'Mate' and 'Cinnamon' are pretty good.
As for 'a single decent widget set', I like having CHOICE. And I'm working on my own... [with an IDE to wrap around it].
So yeah, much of what you said here is the same FUD as always. Since I've been using BSD as my daily OS since around 2004, and doing primarily non-windows development since 2005, I've seen Windows in decline and it's turned ugly, and mean.