You are missing the point.
This is just ONE case. The other guy wasn't able to deal with this ball successfully, and it was totally logical to exploit that weakness. In general, most decent players will probably be able to deal with it ok. But for sure SOME people won't .
I agree tennis is not all about winning. But it's much more fun when you win. And there are times when you really have to dig out and find a way to win. In tournaments, or league matches. Esp in tournament, since you are going home once you lose. I don't see how it will interrupt with player's develop ment. The palyer is finding a way to win, and he has done it succesfully.
It's a pretty much rule of thumb to go down the line on your approach for several reasons. But if the other guy can't hit forehand under pressure, or on the run, it makes sense to go there. Given that his backhand is more solid than forehand.