Could someone please remind me why one would cancel if they are enjoying the service?

Their price went up and now it's not a discount, but rather a competitive price (see AMEX CMS). Actually, the service becomes competively priced based on other CMS's and if you want more services, you can pay for it - an extra $9.99/mo for a pull every day.

Gosh, I hope i'm not missing something here.

* Edited to be more specific.