I like the tip, however, I will never personally shy people away from doing things that are more secure. Having full comprehension of what's going on is important, but that knowledge should not scare people away.

xpubs are the one backup need that I would actually confidently say "Go ahead an back that up on google drive" (you should encrypt it anyway just for privacy, but unencrypted won't affect your security) whereas with private keys, I would never dare say something like that, not even an encrypted google drive backup, mostly because people's passwords are bad! Password reuse and limited imagination and poor ability to do random really have killed the password.

That all being said, it is true that a cold card and a seed backup in steel is probably all the average person needs, but a multi-sig with your mommy and your in-laws with everyone's xpubs on google drive would also be pretty good. It would protect your money from a house fire the same way a steel plate would.

So basically I'm saying, everything is a matter of trade offs and preferences, but don't go scaring people away from things. Explaining how to be safe with it is much better.