Yeah, that was really frustrating. Why do we still have networks delaying regular programming for sports? They all have digital sub-channels and cable-network partners now. Save the sports for the dedicated sports channels.
Months ago, I set my DVR to keep recording Elementary for another 30 minutes beyond the scheduled time, but once or twice, it didn't start until 40 or 45 minutes late, and I had to watch it via On Demand. There was one week where it was delayed a whole hour and they just postponed it a week. That's just unacceptable.
You may have missed this, but sporting events are actually valued highly by human society, going back millennia. Cave paintings in France dating back 15,300 years show wrestling matches taking place. Sporting events can build a sense of community, and discussing the different players and actions in, say, football matches, can lead to lasting friendships.
But to your point about why networks delay programming when there are already dedicated sports channels, you have to understand how advertising works. Networks sell advertising to outside companies--these are known as "commercials". One time sporting events can lead to more viewers (because society values sports, as discussed above), and therefore, more valuable commercial time than regular programming. Thus, networks are highly motivated to shift regular programming in order to air sporting events.
It's true that there are many cable networks and other outlets for sports these days, but you have to understand that not everyone has access to these, and so traditional networks will still have more viewers than, say, ESPN for certain events.
So now that I've explained it all to you, I trust that you'll find this practice, which has a long history and has every reason to continue, quite acceptable. Perhaps your original purpose was to "vent", but a proper understanding of human motivation and behavior should be a sufficient response to your post. You're welcome.
TC