This "manager" is 70+ yrs old and a math genius. We were tasked with creating a web application. He loves SQL and stored procedures. He first created this in MS access. For the web app I had to take his DB migrate to SQL server. His first thought was to have a master stored procedure with a WAITFOR Handling requests from users. I eventually talked him out of that and use asp.net mvc. Then eventually use the asp.net membership. Now the web app is a mostly handles requests from the pages that is passed to stored procedures. It is all stored procedure driven. The business logic as well.
What are the best arguments for not having the business logic not all in stored procedures?? How should I deal with this?? I am giving an abbreviated story of course. He is a genius part owner of the company all the other owners trust him because he is a genius. and quoting -"He gets things done. old school".