There's one tiny flaw in what you're saying:
If you concede a SE game, the only ones affected are you and your oppo. In other words, ONE of you is going to advance, and for whatever reason you have decided to let him be the one.
In the RR, many times not playing the 3rd game will GIVE the victory to your oppo, if he is 2-0. The other players are praying for you to beat him, making a 2-1 tie so they still have a chance.
Or sometimes, if you win the 3rd match it will be a 2-way tie, if you lose it there's a 3-way tie. By conceding the match, you force a 3-way tie, meaning it is possible that NONE of the remaining players will win.
In both cases, it's considered poor sportsmanship not to do your best.
I can only repeat, to you and others who feel the way you do, that it is best not to enter a RR if this is how you feel about it. Because when you enter, you have agreed to abide by the rules, and they clearly state that you must finish all your matches, except in thje rare case that a match is truly menaingless, as described in an earlier post on this thread.
To ask us to put an "exclusion" feature in the tourney registration programming is an hysterical idea, but of course it's not gonna happen. An even better idea, my friend, would be to get in the habit of checking what sort of tourney it is before you push that "submit" button. It's not like the information isn't right there for you to see....