Probably because the app isn't available for the os the TV is running. Your best bet is to not buy a "smart" TV unless it's running android. If you happen to already have a "smart" TV, buy something like the shield and you can run all apps available for android without being stuck with the shitty os on whatever TV you have.
It’s more likely MLB hasn’t developed an app for LGs platform than LG is blocking an app from their platform.
I don't know of any exclusivity deals for apps. Haven't heard of that being a thing.
It's more likely an android versioning issue, where the app is too old to run on the TV.
OP is talking about LG, afaik they roll their own os. Probably not enough demand for whoever is behind the app to make it available on that os
Last I heard LG TVs run WebOS. In 2011 you could buy HP tablets running this. The OS traces its roots back to Palm Pilot PDAs.
Oh, I'm aware of the origins of webos and palm. I still have an old palm pilot sitting around somewhere. One or both of the battery coils broke and I never got around to fixing it.
As for the TVs. I'm fairly certain that while LG os is based on webos, they made some modifications to it and maintain it, somewhat.