The problem is governance. The web sever needs to be patched, the web site configuration needs to be maintained, as does the web application. Bear in mind that a display doesn't live in an IT department, and that developers don't maintain apps - operations does. So if you compare the web server/web site scenario to a single, self-configuring native app (presumably a single .exe and a couple .dlls or something, the .exe is cheaper over a 3 or 5 year lifespan, especially if the .exe works with SCCM and ops can push updates out using WSUS or similar.