It'd be quite easy and cheap for them to simply add sports to the platform. MLB shows every single game over a season, live and on demand. Coliseum are looking at offering MLS etc also, and are saying there would be a discount if you did so. Its quite clearly cheaper. I make sky out to be 1200 a year - that is 8 sports you can get full coverage of for the same yearly price of sky. That isn't including possible discounts as mentioned above
. With regards to randomly watching a game, you'd have more options to do that, to take your cricket example, sky don't often show a lot of series - a similar online cricket platform would show all games, and you'd be able to simply purchase a day or match pass if you wished to watch India v Sri Lanka.
I get that you can't channel flick, but essentially what you're saying is you're willing to pay sky all of this extra money, just so you can mindlessly flick through channels, but you're not willing to pay a one off fee to watch the same random game you'd end up watching whilst channel flicking.
Perhaps in future, on a smart tv you could load different sport providers on to favourites, then randomly flick through to see what is on, and pay a small one off fee to view that game - and you wouldn't mind doing it so much as its nothing compared to the $100 a month you used to shell out to do the same thing.
I'm not saying its perfect, but sky has limitations too. Its also clearly cheaper, with more content available. The only reason it becomes more expensive is because of the monopoly sky currently has, and their insistence on bundling everything together.
Also, in terms of the 'small nz market': systems like these aren't necessarily tied to a nz market. MLB, NBA and NFL stream their services to places all over the world, from the same system. A much greater economies of scale is possible with such platforms than it is on sky, this makes it easier to justify bringing more of different sports into nz as doing so may even decrease their marginal cost per customer.