They were doing that back in 2010. I went to a few conferences where they promoted MongoDB as an all-purpose database that was the "next thing" compared to SQL.

Once everyone realized its shortcomings as a general-purpose database, there was a gradual "oh shit this isn't working" migration back to SQL-based databases.

I think the big problem is that the MongoDB programming model and APIs are very nice; we really need a database that is still relational "under the hood" but has an API that's more like MongoDB.