If it was so easy to replace revenue, then all companies would be selling whatever products CVS will be selling. But it is not easy, an this is an in your face move to shareholders.
But all companies don’t sell all products or services. Companies sell products and services that are within the company’s expertise, or otherwise make sense for the company to sell. CVS believes that their “minute clinics” are a long-term growth area for the company, while tobacco products are a long-term diminishing market.