What is the basis of your claim that they are using this as a way to 'scan mobile devices .. and gather information which they are profiting from'? What information? Profiting how?
Without facts, what you're saying is indistinguishable from any other conspiracy theory.
You say 'operating an internet service to anybody in your area' and in the main it's not "anybody" - it's Comcast customers. Of which you, if you are so affected, are likely to be one. Comcast using their equipment, their facilities, their network and their backhaul to operate an internet facility to THEIR customers.
The long and the short of services like this is that people - where they have a choice - are more likely to choose, or stay with, or be happier paying for, an Internet Service Provider if they get more value from it. If your Comcast internet service suddenly comes with the ability to access that service from wifi hotspots throughout the town or city where you live [and there's a great chance of there being a significant number of such hotspots available in a locale served by a dominant cable operator] then you, as a Comcast customer, are likely to get a good value from that.
Good value equals more and happier customers willing to keep paying the same or more. Simple business. No covert data-gathering and "seeing what people are doing" conspiracies required.