somewhat amused that on a mountain bike forum lots of peeps choose road bikes when the going gets muddy - always thought that was part of the fun!
Depend how you define fun!
I'm all for a bit of slippery slidey action, but on my usual "spin the legs for a bit of fitness in the evenings rather than watch TV" loop there's an option to add in a few miles of bridleway. It's under a foot of mud and took me over an hour and a half to cover 5 miles and would have been quicker to leave the bike at the start, walk it, then walk back down the normal route and pick it up!* Doing that once was a bit different, a bit of an adventure, and when it wasn't calf deep in horse shit, fun. Doing it every night would be self abuse!
I'm currently riding my rigid Singular Swift as it's the best at copeing with they shitty conditions whilst still being a bundle of fun on the occasional dry(ish) decent.
*And it's not the worst one, there's another one which just skirts arround the border of soem fields before droping into some woodsy singletrack, that remained passible even over the winter. It's so wet that water is flowing out of the hillside and down the fields in continuous strems!