It's not really ODM's choice. The suppliers force them to bundle the "unwanted" channels along with the more popular channels. It is their way of getting funding for the less popular channels.
It is a catch 22 situation. Not everybody likes the less popular channels, but there is still some demand for them, and they add a little bit of value to the entire bundle. So if you get rid of them you lose a certain amount of subscribers, if you carry them as is, not everybody wants them and the income is not sufficient to justify them. The solution... bundle them along with more popular channels and those popular channels then subsides them. Everybody wins with minimal fuss.
It's like all the extra crap that Mweb offers on their website (the news, weather, competitions, school homework stuff, etc.) not all of us make use of it, but they add value to the entire offering and are all subsidized by our purchases.
Same with SABC. You don't watch all the programs on SABC (well, some of us don't watch any programs on SABC, but bear with me

)... some of the programs on the Free to Air channels are crap. But they are bundled with and subsidized by the more popular channels.
This bundling and cross subsidisation happens in very many industries. It is a fact of life. If they didn't do it, there would be 50% less channels overall and that result would then appeal to 50% less people.