Which is why I find it uncomfortable when a GM resorts to the aforementioned rule.
For a game that runs any real amount of time a GM eventually has to. For very simplified systems the rules are more open ended and vague, which inevitably means more responsibility on the GM to make judgements. But, even on a very bloated and complicated system like D&D 3.5 edition there are plenty of cases where the rules don't cover bizarre technicalities or overlap in ways that simply won't make sense. Off the top of my head, a rogue can pull out a tower shield, gain total cover from standing behind it, and automatically succeed at a Hide check. There are nigh-impossible shenanigans a wizard with a very low CON score could attempt to wind up with a higher amount of HP than what's normally possible (though it would be unlikely to happen and wouldn't be worth the trouble). And there are a number of rules, especially in the expansion books, that straight up say to consult with your GM for a decision on what the benefits of your choice would actually be.
Of course, I'm sure you speak of Gygaxian bullies that create meatgrinder deathtraps for his amusement or excessively railroady ones who behave like the DM in this comic, but the fact of the matter is that someone needs to run the material, and that someone needs to know all the secrets without giving them away and make judgements for edge cases in the rules or to balance things out for a more enjoyable experience. Those last two words are important, because it can be very easy for GMs to become selfish or mean.