I don't think there's no use for NoSql for accounting, I just don't think financial transactions are served by it. But if you're gathering data on your customers or suppliers for example, sometimes that data doesn't fit nicely in a SQL table structure. It really helps to have options.
In the same way, programming languages are tools, like different screwdrivers are tools. If you have to remove a philips screw, you could use a flat head screwdriver to do it, but it's not the best tool to use. You need to be able to recognize the requirement, and make a reasonable decision on what tools to use to solve that requirement. The tool choices need to be flexible, but not to the exclusion of better choices for that requirement. This is a hard thing to teach. People have a tendency to have favorite tools, and in software where everything is abstract, making the right or even reasonable choices is sometimes very difficult.