Well.. you do receive 400 prestige for re-creating it if it has been destroyed once, which is fine by my standards (costing 200g & 200 piety)
Yeah, but that's the same as for any other kingdom, while k_Jerusalem should be somewhat special. Same rationale as for awarding the huge bonus on its first formation as opposed to the standard 400 prestige for a normal kingdom.
But I mean this only in connection with something like k_Jerusalem falling, title being destroyed, and then someone winning the crusade and recreating it. Or forming it after holy-warring or claim-warring the territory back from Fatties/Ayyubids/Seljuks/Ilkhanate/Timurids/stray GH.
You know, something like forming k_Jerusalem after a crusade in the 1337 start, where it had existed in the past, in history files (de facto 1099-1291, later claimed by the de Lusignans from k_Cyprus), before you started the game. You still aren't Godfrey, but it counts for more than Taurica or even Egypt, Andalusia etc.