That's a good practice, and I think you're right that is what they're going for. I don't think that means you shouldn't consider them, but it does lower their value proposition as the bundle is the better deal.

this isnt a full solution obviously, but I figured it'd be nice to know: Proton lets you set different passwords for your email and password manager, so at least from a security standpoint its not all behind the same password, even if it is still from the same company