Somehow this reminds me of the scene in Back to the Future 3, where a seemingly drunken Doc explains to incredulous far-west folks that people will jog for fun in the future.
And I could add numerous examples of what used to be considered as work some centuries ago and are now entertainment (sailing and skiing come to mind - I'm sure the 16th century sailors would be a bit perplexed when learning that 4 centuries later sailors would sail around the globe without shipping any merchandise not carrying any cannon ).
Maybe, as Tatterdemalion King explains, a lot of what we now consider to be hard labour have turned into light entertainement or hobby in the UFP (I particularly like the comparison of scientists to rock stars).
Anyway, I tend to agree more with this point of view than black campbellq's. Enough off topic now.
I thinkg a UFP civil war could simply occur if old grudges were to suddenly resurface in many core worlds at once. Let's suppose that the VIM suddenly becomes more influent on Vulcan, while at the same time traditionalists take power on Andor and bring back the topic of the Vulcan/Andor war that used to be during Enterprise's time, and we could suddenly have a very high tension between two major worlds of the UFP. Add other members taking sides instead of trying to calm things down, and nasty events are ready to occur...
(BTW, this could all well be a Romulan or whichever species plot to divide the UFP from inside - or even a section 31 plot to enforce the UFP by putting it through a bloody civil war...)
"The main difference between Trekkies and Manchester United fans is that Trekkies never trashed a train carriage. So why are the Trekkies the social outcasts?"
Terry Pratchett