The problem with that analogy is that Linux is widely used in the business sector. The whole of Google's search engine, processing billions of searches per minute, is done on a Linux based platform. IIRC they chose Linux at teh start because it reduced the licence fees they had to pay. Lots of govt orgs use Linux for teh same reason. It's only retail users that are predominatly Windows.
Well yes, I'm talking regular people rather than business.
If decentralised exchanges were fully automated and 100% bulletproof, then there's no reason for businesses to go anywhere centralised. I've no idea whether they will be. I was referring purely to retail.
If we ever get a full on IoT economy going there'll be trillions of transactions per day. I'd assume going through a third party for that would be incredibly cumbersome.
Businesses like Overstock have added altcoin payments using Shapeshift. And Shapeshift is essentially decentralised. So, just as with Linux, I'd say the merchant space will go decentralised before ordinary users do.