It seems that insecure workers may not get it!
In today's technology environment that offers very good teleconferencing and intstant messaging facilities there is absolutely no reason for people having to meet face to face. Having worked for large enterprises like HP where there may be thousands of people working on projects in some form all over the globe you could not get them in one room anyway and you end up teleconferencing. Therefore, there can be only one reason as stated elsewhere, insecure below par workers need others around so they can try and make up for their weaknesses.
I for one telecommute and I am much more effective and productive than working from an office; often I get an idea late at night and go to my computer to work on it there and then. Something I would never do if I had to work from an office.
Yahoo? Who needs them they are probably dieing anyway and this is probably the first sign of their demise.