Not just this, but they're assuming that everyone's server setups are enterprise-grade! People regularly still put raspberry pis and other kinds of low-cost computers on the public internet (William Gibson, for example, hosts hackers.town on a server setup in his (probably metaphorical) basement), and their answer to that is: "Don't do that".
You do not give a single argument on why the complex thing is meaningfully safer in practice.
If security is equal for all practical purposes in either case, this would be the wrong thing to do, because it is easier to fuck up complex things and it's more expensive to manage them.
https://xkcd.com/538/