"Why The MongoDB Hate?" Very simple, because the product appears to be severely overhyped and underdelivered. Your primary datastore is not something you want

"Why The MongoDB Hate?" Very simple, because the product appears to be severely overhyped and underdelivered. Your primary datastore is not something you want to be taking risks with. If you are looking for a toy you can use any DB you like, including Mongo. If reliability is important to you why would you want to serve as a guinea pig for some seriously buggy product? NoSQL has its place where you have a very specific use case to be solved, but your primary datastore of record is rarely one of those. Mongo specifically is being positioned as a general-purpose datastore and because of that (for me at least) it fails to demonstrate any value whatsoever. Every time I ask any Mongo advocate for why it is a good choice the most compelling thing I hear is "schema-less DB" and "speed of development". Guess what, maybe if your database forces you to think about your schema, data layout and the query load you are going to have to develop a more reliable application. Having to think through your schemas in advance actually forces you to be disciplined and prevents you from making errors. Once you are ready to confront the reliability issues SQL databases that had years of hardening against all sorts of risks look like a safe harbor. MySQL is not too bad for Facebook and Quora, what prevents you from properly tuning it to work for you?