I don't think any country should be allowed to put a cap on religious practices that are not hurting anyone else. Obviously no religious groups should be allowed to engage in immoral practices like human sacrifice or something, but generally people should be able to worship as they please.
It does seem contradictory, doesn't it? My reaction is similar to pohnpei's, although I would like to know more about the arguments in favor and against this prohibition. Apparently many people in France feel that secularism is under siege in ways that ultimately threaten its very existence.
From my point of view as an American, this does not seem right. It seems wrong to ban people from showing outward signs of religious faith in schools and it seems wrong to ban the wearing of veils in all public places. France claims that this is a security issue, but I think that it should have to prove that there actually is some sort of harm that comes from wearing veils before France should be able to ban it.