It's not just security, there's a bit of an over-obsession with generalised future-proofing: useful optional proposed protocols have been shot down because they 'assume windows will be laid out on a screen with xy coordinates'. It's a recipe for committee bikeshedding to run rampant, especially with multiple very opinionated parties involved, any of which can torpedo even an 'accepted' extension by just not implementing it. It's a nightmare of fragmentation.
