I don't understand what annoys you so much about that particular belief; it is no more different to yours than Samson's (whose ideas, frankly, will make little sense to most people). In a test of beliefs, in the end everyone is going to have to voice their inner opinions which, on some level, they are going to rate above the opinions of others. The whole thing is structured so that at no level does ANYONE'S opinions have to conflict with each others; the test is purely personal. So why make such a big deal out of it?
If you are irritated that he has found some cheap way out of the puzzle- he did not.
If you think it is unfair that he took a solution that others could not- that is not true, except in that your submission must be in line with your beliefs. But his beliefs will not magically shield him from the consequences of what he decided.
If you are annoyed he took a perspective you didn't think of, then sorry, but that is simply the way it is.
If you are upset in thinking you were deceived about things, then I can only say that you and he were in the exact same situation and simply thought differently; no unfairness was present.
If you are concerned that some people's beliefs will make this puzzle easier for them than others... then literally speaking, yes, that is always going to be true (and Fire stuffed himself, and knew it), but practically speaking you only have to intellectually arrange what beliefs you have in alignment with this puzzle which is not vastly different for anyone, and on top of that the puzzle was NOT easy for Aeneas nor was he even remotely happy with his submission. If Aeneas could have in good conscience been happy with the AI dying like you are he would have thought he was doing MUCH better, but he couldn't.
All he did was react to the puzzle as best he could in accordance with what he believed and that, in the end, is all that can be asked of any player. I am pretty damn sure Castor isn't happy with what he had to put either but he HAS done the best he can and he doesn't seem quite so irritated by other ideas.