No, I agree, but I would argue those guys either don't really care that much about the people around them and their blessing, or they aren't really committed to the woman and are just going through the motions.
I think the difference is that when your event is witnessed and celebrated by everyone you care about, it can simply help make it more real and binding for you if you think it does. Tree falling in the forest type thing. This applies to many events - graduations, awards, sports, etc.
If you don't care about anybody witnessing or recognizing or blessing your commitment, then yeah, may as well do it in city hall by yourself. Which only has meaning if you give it meaning. Like Baka, I think it's pretty pointless, aside from securing whatever legal rights married people have for yourself if you want them. Chances are, if you don't care about having your loved ones witnessing your commitment, then you are truly an island and you don't care about the state witnessing it either.
Personally I don't believe anyone is an island, at least not by choice. If you don't want your loved ones witnessing your marriage, I'd bet you're not that sure about the commitment.
And like Neil says, the even-more-real binding moment is having a child together. Before that point, there are really no major consequences to divorce. After a baby, you are in each other's lives forever regardless of divorce, unless you're total scum.