This is just faulty logic.

openssh is one of the most secure projects. It's developed by the security obsessed (and I mean it in a kind way) folks at OpenBSD.

I, for one, am ready to place for more trust in openssh than in any VPN daemon. The most commonly used ones are propitiatory.

What if there is a 0-day vuln (not exploit) for these VPN daemons? That far more likely. "Securing" ssh with a VPN is just one step beyond of security by obscurity.

If you are afraid of script-kiddies and scanners, let your sshd listen on a non-standard port.