Since you explicitly mentioned fashion, I assume you read this:
> There is a distinction that the industry refuses to acknowledge: developer convenience and correctness are different concerns. They are not opposed, necessarily, but they are not the same thing.
…
The rationalization is remarkable. "JSON is simpler", they say, while maintaining thousands of lines of validation code. "JSON is more readable", they claim, while debugging subtle bugs caused by typos in key names that a schema would have caught immediately. "JSON is lightweight", they insist, while transmitting megabytes of redundant field names that binary XML would have compressed away. This is not engineering. This is fashion masquerading as technical judgment.
I feel the same way about RDBMS. Every single time I have found a data integrity issue - which is nearly daily - the fix that is chosen is yet another validation check. When I propose actually creating a proper relational schema, or leaning on guarantees an RDBMS can provide (such as making columns that shouldn’t be NULL non-NULLable, or using foreign key constraints), I’m told that it would “break the developer mental model.”
Apparently, the desired mental model is “make it as simple as possible, but then slowly add layer upon layer of complex logic to handle all of the bugs.”