Why is that bad? The query plans the RDBMs uses end up being slow. I think it's simply not the case that people are using key-value stores because the query pl

Why is that bad? The query plans the RDBMs uses end up being slow. I think it's simply not the case that people are using key-value stores because the query plans that a typical DBMS optimizer chooses are suboptimal for the kinds of queries most web apps use.