Just spent some time with friends who are just casual internet users. Both spontaneously said that they hate mobile sites. I see no reason to develop one.
Mobile sites are so often done wrong that is not surprising. However, if you done correctly they make the experience more pleasant. That is the point right? A better user experience? If I can use a mobile version and not feel the need to revert to the desktop site then in my book it is done right.
Truthfully, I had them opinion up until recently, however the logs don't lie. People are coming to my sites on their phones and even progressing through checkout even though my site isn't great on a phone. There is a huge opportunity to capitalize on this right now.