So Comcast is proposing charging customers $9.95, minus a $2.50 credit, for using a Roku instead of a second set-top box? What is incentive to the consumer for

So Comcast is proposing charging customers $9.95, minus a $2.50 credit, for using a Roku instead of a second set-top box? What is incentive to the consumer for using a Roku instead of a second set-top box then?