Yes. If anything, people should be using the open source KeePass:
And these are values I very much respect, and I promise I won't act surprised when I get screwed by using proprietary software.
But in terms of user experience, I can't inflict KeePass on the people in my company, especially any non-Windows version.
If you want to train people to handle passwords responsibly, user experience is extremely important, and having to use KeePass would be a punishment.
People would start finding ways to not use it, which is why 1Password is the safer choice in practice, despite being proprietary.
There are various plugins for multi-factor key derivation existing for at least several years already. You just have to chose one that suits you depending on what your second factor is (PKCS#11 token with RSA key, OATH HOTP generator, Bluetooth-based key storage, etc). Platform support may vary, though (so, not sure all options are supported, say, on Android).
Authentication is about proving your identity to a system that has the power to grant you access to something. They can have you go through multiple steps. But with 1Password and KeyPass, you already have full access to your data (it is on your disk). Your password is used not to prove your identity, but instead it is used to derive a key which can decrypt the data that you already have access to.
Services that you need to authenticate against face different sorts of threats than those which are based solely on encryption. An authentication system protecting high value data simultaneously make multi factor authentication possible and necessary. For encryption based systems, MFA literally makes no sense.