yeah...like everyone else has said, there's a good chance that you won't be able to get through to your friend, and he'll have to figure things out the hard way. As for love being blind...more power to you, those that love like this, but I can't fathom my heart fooling my brain when it comes to a woman that I'm attracted to. We'll stop there, since there's a lot of people that will hate me for saying that alone.
Lastly, if he's 23 and hasn't had a "g/f" yet, that's totally fine. My best female friend is "dating" (nothing official, but they've been seeing a lot of each other) a new guy, who's really great for her. Lots of accomplishments, good looking, well built, good job, yadda yadda...and he's never had a g/f before. Definitions differ, and some people just don't want serious relationships until a certain time comes.