Unfortunately as we have seen, people don't like that advice and refuse to listen to it. At least one person has lost 1000 DRK as a result. My guess is at least 5 more MNs are compromised within the next month.
As said, if they do it correctly. But in practice that won't be the case, especially because the screw up wouldn't be visible to an unexperienced user following a guide. Their concern is that the MN is visible, which it would be. The security hole they left is invisible, to them.
Ok -- so your concern is about MN integrity, I thought you were worried about newbies losing their coins from unsecured MNs.
It's a valid point, but I don't see an obvious solution other than making resources available for best practices, and designing darksend such that some % of compromised MNs doesn't compromise the anonymity of the transaction.