http://bugs.winehq.org/show_bug.cgi?id=19182
--- Comment #54 from Rosanne DiMesio dimesio@earthlink.net 2012-08-02 09:17:10 CDT --- Well, since people are quoting my earlier words, I suppose I better weigh in.
Philosophically, I stand by my earlier statement; IMO, adding mimetype associations to the host system instead of just to Wine's explorer goes beyond mimicking Windows. If I had my druthers, it would be off by default, with a simple checkbox in winecfg to turn it on for people who want it.
But as a practical matter, working around this is trivial. Adding the override to .bashrc quashes it once and for all for that user, and the instructions for how to do that have been in the FAQ for over three years. I do not think adding a single line to a plain text file that does not even require sudo to edit is beyond the mental capacity of normal users.
I also think some people are greatly overstating the dire effects of not turning it off. My experience (on KDE) before I disabled it entirely was that mimetypes were added to the bottom of the list of associations, so the default for the system was not changed: LibreOffice still opened doc files when I clicked them, even though Wine had added a more than a dozen associations for Word (none of which worked, btw) to the list. If someone is seeing Wine's associations supersede existing defaults, IMO, they should file a bug for that, because I don't think that's the intended behavior.
As to the suggestion for some sort of complicated dialog to pester users about this every time they create a wineprefix, personally, I would find that MORE intrusive, so if someone decides to add that, please make sure there is an easy way to disable that once and for all.