I would love it if this were removed (or perhaps better to just make it very unlikely to work), and have more events that grant claims inserted into the game. In the first CK, you could get claims on another noble if the publically insulted you at tournament, etc (maybe have these time sensitive, only good for a year after the insult). Maybe we have the Pope send a request to those with high piety to invade counties with heretics or excommunicated rulers in them (and give another incentive to have higher piety). Other methods, would give more flavor in my opinion.
Fabricated claims are more historical than getting claims from insults. What would be awesome a and add flavor (but might be very hard to implement) would be the possibility to fabricate your lineage. This was a common way to become a pretender, improve your prestige, or get fabricated claims.