I think FFH is in a somewhat unusual position where mods are concerned in that it has a team with excellent programming, artistic, graphic, and narrative skills, and seemingly the time and commitment to follow through their ideas. I have been involved in or followed the development of mods for many games in the past that have had some of these qualities, but it is very unusual for them all to be present at once. In such a case the advantage over commercial development is obvious - no deadlines, compromises, or dumbing down to hit 'target demographics'. Not getting paid does have it's advantages as long as you're financially secure then, but as someone who is skint most of the time myself I can completely empathise with those giving up so much of their time for our enjoyment while working away a regular 9-5 at the same time. It is appreciated!
