That's great that you're happy with it. I'm not drilling through my roof to install an ugly dish and I'm not paying for a land line that I don't need. (By the way, fewer and fewer people have land lines.) I've done the math and DirecTV would be considerably more expensive for what I get, so I've never believed that satellite was that cheap. I don't like being tied into a contract (thanks, Verizon!).
MLB won't be the ones who see revenues drop. I'm sure DirecTV would make a lucrative offer, and they still have the MLB.TV service. (Maybe their plan is to ramp MLB.TV sales up by shutting out the cable market, which would be a stroke of evil genius.)
You don't have to have a land line to have satellite TV regardless of what you might have heard. The only reason that Dishnetwork and DirectTV tell you need one is to facilitate ordering pay for view features. If you have a landline connected to your satellite box, then you can order pay for view using your remote. You can still do pay per view via the internet or from your cell phone. Of course the satellite guys have figured out that you'll order more pay per view if you can use your remote. They may tell you it is 'required' but if you push you'll find out that 'required' is not really required to subscribe to their service.
But other than that you are correct, there are other disadvantages to satellite vs. cable. Of course, in my neck of the woods, cable is not an option so there are advantages to satellite as well. BTW, in my neck of the woods, over the air is not an option either.