Well think about it. By forcing non-paying users through their web interface, they can splash them with advertisements. So in effect, paying for use of the service. If you sidestep the advertisements, then you're *completely* freeloading. So given that, they made a compromise and allow you to pay for the service of avoiding all the ads and using POP3. What's wrong with that?
If you have no problem paying for "certain services" well, in my mind's eye, this looks like a service worth paying for.
Calvin