Most people don't care about web cams at work. Most of my meetings I'm looking at a power point, or some other screen and so the person speaking isn't an issue.
A few people enable their camera all the time, but not everyone. In the few meetings I've been in where everyone is asked to turn on their camera so we can see each other (in some sort of team terms) at least one person says they are in a family situation where they cannot.
Cameras are a must when calling grandma. In an office situation they are at best a nice to have.
I think its more that laptop manufacturers don't care because no other OEM has made a selling point of it. Its a virtuous circle - some people care about a specific feature, some OEM makes it a selling point, more people start talking about it, OEM B calls an emergency meeting and asks for the feature to be in their new laptop line, they spend advertising $$ promoting it, more people get to know about it and ask for it, more OEMs start including it.
