It was worse than insulting, it would have limited the people using it, to the small list of sites (compared to the whole Internet) decided by others. It's like

It was worse than insulting, it would have limited the people using it, to the small list of sites (compared to the whole Internet) decided by others. It's like saying to someone: here's a free communication mechanism, you can only use it to access services run by us ... and in the process, be made to view our ads willy-nilly. For Internet newbies, it also has the side effect, that many of them might not even get to know (for a while, or ever) that other / better sites existed.