The one language argument, as far as I can tell began when people tried to share code across the server and the front end, it sort of worked for one persons use

The one language argument, as far as I can tell began when people tried to share code across the server and the front end, it sort of worked for one persons use case but nobody else really had much success with the endevor (at least that I'm aware of.) That argument is a pretty bad one and is the one most people like to assume people are talking about so they can make fun of it. The real argument, at least in my mind is that you can specialise and pretty much run your entire stack completely in js with only a bit of json and some html. Build tools, database access, deploy tools, dependency management, server side code, client side code, its all JS. For me, I don't agree that it matters, I don't even think having a diverse stack takes much longer to learn. But I do understand the fanfare for it.