Most of its protocol standardization bodies use an authoritative and disconnected approach to defining services with little consideration for what the market wants.
Specifications take a long time to define, even longer to implement and then often miss the target.
That may seem like a harsh assessment, but look at a century's worth of PSTN development. The phone network still lacks any common directory and user-friendly name resolution. Phone numbers are hard to remember and the 12-key telephone keypad is an albatross. The ITU-T has developed a thick series of labyrinthine specs that are too expensive for anyone to implement. Still, H.323 won't improve the user experience anytime soon.