BaaS is definitely one of the greatest opportunities that are emerging. It will be played initially by the big players that already dominate Cloud Business. An opportunity for Google, Microsoft etc to dispute with Amazon.
But I believe that in a second stage, these companies also compete against decentralized solutions that although more expensive will offer more customization and security in the long run.
Microsoft and Google have already a BaaS, Microsoft is one of the leading company with Deloitte and IBM. Amazon is brand new with it. But yeah I agree, the major players in the technology industry will surely have the monopoly
Their products target companies for their own use, to create private blockchains. Why a company should care about "decentralization" while its goal is something totally different and the blockchain is 'private'.
An example, Insurances could use smart contracts for a blockchain-based automation protocol. Do they have an advantage with decentralization?