I think an important thing that should be mentioned is we are not our characters, we simply write for them specifically. A goal for any writer/roleplayer is to mutually create an interesting story and one of the best and most effective ways to do that is conflict. Touchstones can be useful in that they create a conflict, a motivation for a character that the character is actualy -doing- something as opposed to idling in Elysium for days on end hoping to catch the next piece of gossip and then to do nothing about it, which is damn tedious.
It provides a personal plot to your character, how their past catches up with them and what will they do to overcome it. We as players should take the responsibility of taking the touchstones and making it interesting, does your character actively work to improve the life of their touchstone, or do they need outside help from another coterie to ensure that a particular building is protected from hunting because their touchstone resides there.
Open any good book or watch a good movie and you’ll find forces actively working against the characters, especially characters at their absolute lowest point, Frodo or Bilbo Baggins were just normal hobbits who had to accomplish what warlords and immortal beings would never do ,as an example. It’s a character that in the face of complete adversity who still pushes, fights and survives for their belief or goals that makes them interesting.
Your character would be inexplicably dull if they didn’t have something to fight for. Harry fought for his home at Hogwarts, Neo fought for Trinity and Zion, I mean jeez even firggin Mario is all about Princess Peach being kidnapped. If these characters didn’t have their ‘touchstones’ then we wouldn’t have an interesting story.
Lastly touchstones add a dimension to your character that shows they were once human not just ALWAYS a vampire. A complete sociopathic vampire with absolutely no humanity would be boring, not dealt with and avoided by other vampires, this vampire wouldn’t be roleplayed with because well, who would want to spend five more minutes with an axe-murderer. Our characters still hold common sense and the values they held before their embrace are still at play, there wasn’t a reset button on their beliefs when embraced it just became twisted and corrupted, its not the end of the world but more something to make of it.