It's not that simple. Say you get 10% of season ticket holders paying for it, they will want a quality of service that makes it usable. Most will want to use it at half time so you need an infrastructure that covers the whole ground; stands, concourses etc. You need to be able to give out a...
There are only a lot of people there for about 3/4 hours once a week, 40 weeks a year. The networks aren't going to invest in the infrastructure for so little return.