I find it strange when people adhere to these extremely dogmatic ideas about stored procedures. They appear to be either on one end of the scale or the other, ie. they either put all their logic in to Stored Procedures, or refuse to use them at all.
Of course, the reality is that people who use them reasonably do exist and are probably in the majority. You just rarely hear them talk about it because I suspect that they hold the same views about Stored Procedures, Constraints and any other DBMS feature as they do with any other software development tool ie. Use the right one for the job.
Yeah. Lot of the time, for a CRUD app, the who layer between rendering and data storage doesn't really do much besides validations, and those can be in database, so whole middle layer can be unnecessary.
Sometimes, the logic has to be in database, because it is single point of truth and because many application servers are hard to synchronize with regards to "you get max 3 attempts at login" or "you have to have enough balance to do bank transfer".
Sometimes, lot of your logic is in database, because database can do a lot of things in really fast and practical way, like aggregation and reporting and various data exploration tasks.
Sometimes, the database is just dumb store of object oriented data.
Of course, the reality is that people who use them reasonably do exist and are probably in the majority. You just rarely hear them talk about it because I suspect that they hold the same views about Stored Procedures, Constraints and any other DBMS feature as they do with any other software development tool ie. Use the right one for the job.