For a web application database, from a security standpoint only, what are arguments counter to the point for an sp only solution where the app db account ha
It's an imperfect analogy, but I like to compare the tables in the DB's "dbo" schema to "private" data in OO terminology, and Views and Stored Procs to "public." One can even make a "public" schema separate from the dbo schema to make the distinction explicit. If you follow that idea, you get a security advantage as well as an extensibility advantage.
One account (not the web app's account) has dbo access and owns the database, and the web app connects using another account restricted to the public-facing structures.