Selection Sunday and Final Four on TBS: huh?

The Final Four and Selection Sunday today are on TBS, not CBS as in the past. Are CBS executives just stupid? First of all, there is around 10% of this country that does not have cable at all, with only local channels and no streaming, and there is another 10% or so that are streaming only, and many streaming packages do not carry TBS. These stats guarantee that programs on Cable have lower ratings than programs on network TV. Why would CBS decide to have lower ratings for the Final Four? It makes no sense whatsoever that I can think of.