I did this for the very first external web app built for Bankers Trust Company back in the day. SQL Server back end with (classic) ASP on the front end. Even if someone had gained access to the web server, they wouldn't have had access to anything they shouldn't have. I built web apps, an online store, and a learning/video website using the same tech around the same time and they worked without issue for well over a decade. So, there is something to be said for this approach, though I wouldn't build something like this today.