Ph.D.s are really tough. You live below poverty, for about 5 years (although you probably have stable housing and pay so it could be worse). Your workload will fluctuate well above the coveted 40 hours a week and may eat up weekends and holidays if your research gets out of hand, either because the project is behind or because you are behind. Unless you plan to become a professor your career would have been better off if you were working, even in science fields. You go to a school in a random location then do a string of post-docs in random locations. The two body problem happens because your career path has become inflexible. You feel bad about quitting early, which there's a good chance you'll do because 5 years is a long time for anyone.
Those are some of the better reasons not to pursue a Ph.D. The reasons you gave are useless and condescending - no wonder your friend is ignoring you - and I actually disagree with your central point that pursuing a Ph.D. is a bad alternative to not finding a job.
I would even surmise your friend is better prepared for it than you might think because he is not approaching it from the standpoint of having glorified it through all of undergraduate. Perhaps he'll leave for a job in just a year or two. In which case he had a roof over his head (you know, literally) for two years, and good for him.