The 7-11 and Mystery 7 would both be won by default within a perfect Pyramid show, unless I'm forgetting something.
On Price, a "perfect show" is a good thing that a producer might intentionally aim for once in a while. It's good to see lots of people winning things, especially if it's a special episode. Plus Bob usually made a big show of calling it out and making a big deal out of it so that you as a viewer were trained to look for it. Nobody "loses", the only real downside is the budget hit.
On most other game shows, especially competitive ones, a "perfect show" as defined by these examples is a bad thing from a producer's perspective. You don't want shutouts to happen too often. Nor do you want the game to appear too easy or too one-sided. If no Whammies are hit in a PYL episode, for example, it may mean the producers need to allow for more spins and put more Whammies on the board. If a Family Feud shutout happens more than once in a blue moon, it may mean the producers need to schedule some tougher surveys to give more teams a chance to steal.
As much as I love the occasional rout (game shows and even sports), probably more often most at the very least, I have to agree I like the competitive nature of everything. Otherwise you'd risk losing an audience. The main problem I have with a competitive game is the common upset (or a valid mistake that would cost the favored team the game). A couple examples include Match Game & Family Feud.
I probably shouldn't have an issue with the Feud, but sometimes I hate when they sabotage the third question whenever a family wins both of the first two questions. That method helps to avoid a quick rout, but the problem is the family that should've won after three rounds could lose outright for possibly missing the 4th question (going 3-1 before Sudden Death)
In Match Game, if it's a close game, you could give a great response for the celebrities to match, but you only get 5 of 6, whereas your opponent that you dominated "back-doors" into a win (getting 6/6 or 5/6 plus winning the tiebreaker)
Similar to perfect games, the painful losses are rare, but I'd prefer to have a safety net if I were the better participant. If it's a competitive game and both players/teams are equal, then, for me, it's different