You clearly understand the exact problem he had - you're detailing it perfectly - you're just not connecting it back.
They paid the 300 bucks for the online version of Sunday Ticket. All but 1 of the games he was interested in was otherwise available to him for free as part of the national broadcast (Thursday, Sunday or Monday Night) or perhaps even the "top" game that week outside of his local team (how Fox and CBS alternate the double-header every week). So, in the end, they spent 300 dollars to watch 1 game on TV.
Right, but that is due to OP's ignorance. The Thursday, Sunday, and Monday night games more most of the coming season are known when teams release their schedule around the time of the draft which is months before the first kickoff of the season. The only "wild card" is if a game is flexed after Week 10. But that is a "risk" one takes when subscribing to Sunday Ticket. If OP was dissatisfied it's due to his own laziness not to check the schedule before subscribing. His team happened to be playing great.
Honestly, I'd rather be in OP's position and spend $ on Sunday Ticket only to have my great team get consistent free national air time than spend the money as I do on ST and end up not watching the last 4 games because my team is eliminated and too painful to watch.