A minor correction. It imports the text defined stuff into memory but it doesn’t save them back out to the JSONDB. It’s a little bit of a quibble but I think it’s an important distinction. The JSONDB is just the representation of what’s in memory as it gets written out to disk. From that perspective, the JSONDB and the text based configs (JSONDB is itself also text) are two ways to load stuff into openHAB’s memory and data structures.
But it could be possible to write out the YAML that we see in the code tab. And there are some use cases where that makes some sense, e.g. for more easily sharing and importing rules from others. I agree, writing out to .items files and .things files and .rules files syntax is unlikely to be supported.