For example, here people are asking why go to the swamp on day 145? But the fact that there's an open Dragon Utopia standing there is apparently not noticed.

The Dragon Utopia is exactly what is noticed. But a Dragon Utopia can be taken with a scout hero like Crag Hack, so as not to distract your main hero.
Regarding various cheats and maphacks as well. I just want to understand what reasons one could have to go there.
For instance, one of my recent games. Panic. Three passes. A horde of magi along the road, a horde of earth elementals off-road, and a teleport along the road behind a stack of vampires. I go through the earth elementals, run into the opponent and GG. The opponent later watches the saves and asks, why didn't you go through the vampires? They are closer, and there are goodies behind them. And I have nothing to say in response, I just went there and that's it. But I'm a noob, it's hard to find deep meaning in my gameplay actions. Here, a super-player is playing. I just want to understand the logic. I'll say more, if the game hadn't been postponed, I would have been 99% sure there was no cheating. But here the game is being postponed, and after that a third eye is opened...
I just want to understand, primarily for myself, what this was — genius that I'm not meant to comprehend, or still cheating.