There have been several times in my career where I have missed full SQL support in MySQL databases other people have setup and left for me to maintain. Choosing MySQL isn't the worst thing one can do when building a new system, but just because the initial designers don't intend to use advanced SQL features doesn't mean future use cases wont benefit from full SQL support.
Indeed. Just these days the lack of materialized view has been giving me troubles. It would make a certain process about 50 times faster without touching code at all, and it would take me all of three queries.
Granted, the real problem is a poor design of the system, but materialized views would enable me to improve what others have left behind.