That can happen with pretty much any technology if you hire people who can't learn new things. The current de facto tech stack for building SPAs in ClojureScri

That can happen with pretty much any technology if you hire people who can't learn new things. The current de facto tech stack for building SPAs in ClojureScript seems to be Reagent + Re-frame (or something built on top of them). It's conceptually so close to React + Redux that I have a really hard time imagining a Redux guru who wouldn't be productive with Re-frame in two weeks. Then of course you can have jQuery developers who absolutely cannot work with React and probably never will, and possibly vice versa (never seen that tested). Back in the day AngularJS was cool but much of the code written with it was horrible, because people wouldn't work through the tutorial which explained how to use it as a tool, not a footgun.