Well, so do I. But let's first recap what seem to be the opinions of the majority, one or another...
In the pro corner are mostly practising Muslims, who consider this type of robe as something desirable, if not mandatory, in order to live by the tenets of their religion. The exact reasoning behind this requirement are various, but not really relevant for this discussion. Alongside Muslims, there are some free speech supporters and libertarians who may support this as a person's free choice and/or self expression.
In the contra camp, the vast majority quote two issues: that forcing women to cover their faces is oppressive (even if they claim to do it of their own free will - then it's attributed to peer and society pressure and oppression), and to a somewhat lesser extent security issues (not unlike not allowing motorcycle helmets and balaclavas into banks). To a much lesser extent, and most likely to be on the wrong side of the argument are those who insist that Muslims in non-Muslim countries have to adopt an outer appearance as close to the hosts as possible.
As you may have guessed, I tend to disagree with all camps outlined above. In a nutshell, my position on this is that Muslim women are, of course, free to wear whatever they want (obvious security exceptions, to which they tend to bow anyway, notwithstanding), whenever and wherever they want. But, if they do, they really do it at their own peril. And no, I am not saying they should fear any sort of retribution. However, they should be prepared to be excluded, in a very soft and passive manner, from any society where hiding your face is not customary.
As I am pretty certain that what I just said will be easily misinterpreted, I'll have to flesh it out a little bit more. It will probably help if I spell out what I, personally, find is wrong with covering one's face where this is not usual practice.
Quite simply, in societies where people walk around with their faces freely visible to anyone who cares to look, people tend to become adept at, but also dependant on, being able to judge other persons' state of mind, mood, intentions by a quick glance at their face. Humans are very good at that, you know. We've been evolving for millions of years to be able to do it. Not to mention that even animals, and especially primates and apes are also very good at this. Remove this ability from someone who has spent their entire life (not to mention their species' history) perfecting this skill, and no wonder they become wary, even distrusting. Yes, eyes can tell a lot, but they are hardly enough (note that some Muslim head gear hides even the eyes). There's also the issue of voice almost certainly being muffled a bit by the cloth in front of the mouth.
So, without such vital clues, how is one to communicate with ease with someone covered by burqa or niqāb? I know I am always finding it more difficult, and always with a niggling feeling that there's something missing, something essential. The net result of this is that I try to avoid having to deal with covered women if I can help it. And trust me, this is not because I mistrust them, or think they they have something to hide, or anything like that. It is just because I feel uncomfortable not being to see any facial clues as to other person's state of mind, and not least because I feel the exchange is unfairly slanted against me, as my facial expression is freely available to the other side.
So, in the final analysis, as far as I'm concerned Muslim women can continue wearing whatever they want on their heads. If they do not feel oppressed by it, who am I to judge. Also, I do not fear that any of them are potential terrorists. Certainly no more are than their bare-faced male counterparts, Muslim or non-Muslim alike. No, the problem is, I feel something has been taken away from me when it comes to face-to-face (face-to-burqa?) communication, and what's worse, it's just me that's losing out.
Therefore, if a self-imposed exclusion from communication with otherwise well-meaning people is something Muslim women are happy with, then they should by all means cover their faces as much as they want. And all the while I will support their right to choose to do so, and all the while I will expect them to respect my unease and unwillingness to deal with people who hide their faces from me.
There, I said it. The shooting can start now...