I suspect hg serve is fine for temporary use, but it's not really designed as stable, long-term solution. As you say, it lacks authentication, which isn't ideal (or allowed at all) in some circumstances. Also, it needs to be started manually, so it needs some sort of supervisor process/start-up script to be set up.
Obviously this isn't some horrific burden, but it's still more demanding than the basic server set-up for some other DVCSes. The original question was about the reasons for the relative popularity of different systems, and if we're talking about people who are making decisions about a DVCS for the first time, they're not experts already and this stuff probably does make a difference.
Obviously this isn't some horrific burden, but it's still more demanding than the basic server set-up for some other DVCSes. The original question was about the reasons for the relative popularity of different systems, and if we're talking about people who are making decisions about a DVCS for the first time, they're not experts already and this stuff probably does make a difference.