Ultimatums just shift responsibility of decision from you to another person.
By all means, tell him what it is you expect from a partner. All potential couples should have this conversation. Some even discuss & negotiate points, esp if someone feels the other's expectations are unreasonable.
I don't think this is your problem, however. This guy is not suitable for you. This is a totally fine conclusion for you to come to.
Once you have the conversation, then the onus is on you to move on & find someone else. Its not a bad thing to do, provided you are kind. Might give him something to think about, which could benefit a future partner.
Second thoughts can generally be amended with judicious action; injudicious actions can seldom be recovered with second thoughts.
--Cyteen by C.J.Cherryh