It's strange that we do not have a 1187 bookmark, I mean, I thought we have had it since CK1.
I mean, not only crusading (that can be done in 900 if they want to), nor only the 1st Crusade, others crusades and post-crusade historical setups (Crusader Kings-doms) are interesting and definitely at the heart of the game. Already established crusader states create new dynamics aswell : there can finally be another crusade target than Jerusalem, Muslims are up for Jihading the region too.1066 is just a couple of decades before the Crusader era; most of the key individuals of the First Crusade are alive, but generally not ruling. So you can't start as Godfrey of Bouillon, Bohemond of Taranto or Raimond of Toulouse, but you can play as their relatives (fathers for Godfrey or Bohemond, brother for Raimond, and note that Bohemond, at least, is set to inherit his father's title as primary heir).
I too would love some "rail roading" i enjoy seeing real life historical characters at certain start dates.
i frequently would start my game around 1204 or 1337 bookmarks.