I'm not going to list all the small advantages of the RISC OS desktop, wich make it a better GUI. If you have forgotten what most of them are, why not use RISC OS again for a few months and re-discover usability. Or try to find the list someone once made (i think it got published on the RISC OS products directory) with about 130 ways in wich RISC OS' GUI is superior to most others.
Of course I have used modern UNIX/Linux desktops. In fact I use more modern Linux desktops than most Linux users, because I like to compile bleeding-edge versions myself to try out the newsest features. However the problem with Linux desktops and Linux desktop applications is, that they don't always work very well together. An example that I will never forget (because it took me ages to figure out what it was): I once had a problem with printing from OpenOffice.org under KDE. No-one else had this problem, and after a lot of experimentation, it turned out that OpenOffice would not print via the IPP (Internet Printing Protocol) to network-printers if the ODF-file was loaded from a SaMBa share through Konqueror. Other applications did this fine, though. After one year the OpenOffice.org development team had not fixed this bug, since then I have not checked again, it might still be there. This is just one of hundereds of such cases I have encountered over the years. There are plenty of Linux tools wich don't support WebDAV and why should they? Why is it not possible to mount an FTP share into the filesystem, like it is possible with GNU HURD and RISC OS? That way all applications with support for loading and saving files from and to the standard filesystem would benefit instantly. Also with all these highly specialised solutions, you also need support for them on the server and they usually open up additional security holes as well.
As for writing HTML by hand: Has it ever occured to you, that some people might prefer not be limited by the tools wich are provided by graphical web-design applications and might thus prefer to write HTML by hand?