I applaud him for his intentions and honesty but I would suggest this is going too far as I would be comfortable recommending my luddite mother invest a couple thousand on the side and store it in the insured multisig vault with coinbase. People should diversify their investments and that includes partially investing into Bitcoin.
Really?
If your luddite parents' computer might already be compromised, they cannot securely connect to coinbase (or circle or any other easy-enough-for-a-luddite-to-use service) to set up an account. The might THINK they're connecting to coinbase/circle/whoever, but malware could be man-in-the-middle attacking the website they're looking at.
They think they're opening an account at coinbase/circle/whatever... but they're just giving the attacker all their bank account information, getting bitcoin 'deposit' addresses from the attacker, etc. Your parents will have no clue until their bank tells them about odd wire transfers or they try to send bitcoin somewhere, it fails, and coinbase customer support tells them "Sorry, can't help you, you don't have an account with us."
I would say the same about traditional online banking, except your luddite parents almost certainly already have a relationship with their bank, and the bank already knows their name and how to contact them. And it is harder for an attacker to man-in-the-middle the fiat banking system and get away with it, since identities are tied to bank accounts, wire transfers, etc.
I don't know how the "Bitcoin for Luddites" problem will be solved. Maybe hardware wallets, maybe hardware authentication tokens, maybe Apple or Google will get iPhone or Android security tight enough to trust, maybe it will take "come to our branch to set up an account" to get good-enough security and usability.