I dont even knew Peter Todd before this, but i have to agree with him on that one... reduzing the block time is not a good soluction for a lot of reasons, bitcoin should be considered money, and its normal to have services working on top of it, just like VISA work on top of FIAT... you are talking about instax, instax is an feature on top of an central pseudo-descentralised autirity
Instantx is a transaction whose funds are locked by the masternode network until the miner network confirms it through block writing
(EDIT - which prevents double spending and confirms in seconds). Can you elaborate on what "central pseudo-descentralised autirity" means?