Back when I wrote in the option for a branching campaign it was not exactly "demanded" by our set of scenario designers at the time but they did see it as the next best thing to sliced bread (TM).
However the reality was that almost next to no such User Campaigns ever saw the light of day. They need the creator to make a flowchart of the campaign flow - and any changes to thet are painful, should he change his mind and want to make a tweak to it.
The same is true of the competition play PBEM Tournaments option - "Oh yeah!! we gotta have that it will be
really popular on the blitz and other competitive forums!!!" said our then playtest team. I do not think that anyone
ever actually played the tournament feature bar a couple of simple internal play tests back when it was written, waay back in the MSDOS days. (I have often thought of commenting out the start page for that feature in a release, just to see if anyone
actually noticed and complained
)