There's an interesting parallel between ear-seekers, rooms full of silent monsters and the like and the belief that in d20 D&D, the PCs only meet monsters that will provide a level-appropriate challenge. In both cases the environment is changing, in fairly implausible ways, to fit the PCs. The environment seems to know about the PCs and warps in strange ways so as to always challenge them. There's a really clear example of this from Dragon #26, Notes From A Very Successful D&D Moderator (sorry Janx) -
The old crazy dungeon with its traps arms race, and the new tailored encounters are both examples of gamism. Encounters are always a challenge, no matter what counter-measures the PCs employ or what level they are, relative to where they go. Both are criticised for a lack of verisimilitude. The counter to this is simulationism - ear seekers don't exist, traps don't escalate, encounters aren't tailored.
I don't mind the quotes, so much as holding them as sacred law. Umbran summed it up really well, but I must spread some XP around before I can give him some.
With the story you cite, my beef with it isn't verisimulitude, it's the GM is playing adversarially and using out of game knowledge to boot. The jello story is just funny, and a rational line can be traced as to how an NPC might know it and target the PCs (or adventurers in general).
But the pit trap is a clear case of deliberately thwarting player planning for the sole purpose of making them go into a pit trap. That's a railroad. And the sad thing is, he's chewing up PCs, just so he can have the perfect pit trap that kills a PC.
One positive trait though, is that it seems like the GM isn't changing the pit trap mid-encounter, thus if they outsmart him, they get past the trap. But the next trap will more than likely be designed to thwart those PCs and their latest solution, despiite the trap being centuries old and the thought never would have occurred to the creator unless he saw the PCs latest innovation (which he would have employed on the first trap in the first place).
The result of this pit-trap shennigans is that eventually your PC will diie from a pit trap of some sort. And so will your next one.
Certainly, it can be a fun mental challenge to face a trap that you have to outwit. But the story demonstrates the GM bad behavior that is analagous to the PC Chain-Fighter. One trick ponyism. Which the GM is technically allowed as many one-trick ponies as he wants.