The case of some Orthodox Jewish men refusing to sit next to women on an airplane is but the latest volley on the part of so-called "religious freedom" proponents to in fact restrict the freedoms of others in the name of their religion. Similar cases have emerged across the country by folks from other traditions. What these cases share in common is a confusion (or maybe not) between the freedom to practice my religion and my desire to force you to abide by my religious beliefs as well. It's an important distinction, and I don't really believe the proponents of this kind of "freedom" are so foolish that they don't understand the difference.
The truth is that when we do business in the public marketplace or travel on public transportation, we give up the right to decide who we will do business with or who we are willing to sit next to precisely because we are in public. We are free to make those choices in our private homes or houses of worship as well as while we are on or in other private property that we own. When we venture out into public space, however, we surrender the right to decide with whom we will interact. That's the nature of public space.
In the case of the Orthodox men not wanting to sit next to a woman, the truth is that - with all due respect to their religious tradition - the broader culture has determined that women are equal to men. This makes their request to be moved no different from requesting to be moved because your seat mate is a person of color. The request not only need not be honored, it shouldn't be honored because the religious believers have voluntarily entered the public domain. It's really quite simple, and it has nothing to do with religious freedom. If you want to control who you are going to travel with, you need to drive your own private car or charter a plane - and pray to God that the pilot isn't a woman!