That's certainly true, but I can take the same write-up and run with it. Maybe the PCs can't join and earn X when they are promoted to Scion, but the nobles in the city who are Scions will have that little extra. The same with goals, history, etc.
What I like to see are levels/ranks in the faction, with little extras that come with each rank. As well as a list things that will improve your standing with the faction. These extras don't have to be Earth shattering, or even combat related. Even a simple 20% discount on potions and alchemical items from the Alchemists Guild is a nice perk, or information about a dangerous ruin in the Messedup Mountains.
Like was mentioned earlier, I also like to see faction goals and its history. I want to know why it was founded, who founded it, what it has been doing for the last 1200 years, etc. Important NPCs are also good.
If the factions are built into a specific setting and not just a stand alone faction book, I also like to see which factions are rivals, enemies, friends, won't speak to, etc., as well as the reasons for those feelings. Oh, and the major locations you can find each faction.