This is going to be one of those wonderful games of iterated group prisoner's dilemma, in which one member of a formerly functioning cartel has just publicly announced an intention to always play Defect.
-Pay own legal fees, saves portfolio company money
-Better terms/relationships with investments attracts more, higher-quality startups
-Higher quality startups will likely be the big hits VCs need to be successful
-Attracting high quality startups forces other VCs to work with us on future and larger investment rounds