Sometimes tech reminds me rich, bored, stay at home SO's that are constantly redecorating their house. Not because they need it, but because they are bored and the next trendy design looks cool anyway.
My guess is he is a consultant hired to do a typical project (i.e., help me move X into the cloud, help me re-architect our data model for big data, help me implement AI for our dog walking app) and at that point he just shows them they aren't ready for it or flat out don't need it.
It's just my guess, but it's what consultants do. The bad ones are happy to take on your project and charge you $400 bucks an hour. The good ones unfortunately, deal with the dilemma of turning down lucrative work in the spirit of doing what's right.
After all, if they think they are going to hit big data scale and want the tools to handle it, you aren't completely a bad guy if you help them do it right, especially if you've already advised them not to do it.
No need for clever optimizations - Moore's Law will bail you out a lot of times.