Because if that possibility exists, you should not necessarily precommit to cooperate with Omega, since that risks being punished by No-mega. In a universe of No-megas, precommiting to cooperate with Omega loses. This seems to me to create a distinction between the questions “what would you do upon encountering Omega?” and “what will you now precommit to doing upon encountering Omega?”
I suppose my real objection is that some people seem to have concluded in this thread that the correct thing to do is to, in advance, make some blanket precommitment to do the equivalent of cooperating with Omega should they ever find themselves in any similar problem. But I feel like these people have implicitly made some assumptions about what kind of Omega-like entities they are likely to encounter: for instance that they are much more likely to encounter Omega than No-mega.
But No-mega also punishes people who didn’t precommit but would have chosen to cooperate after meeting Omega. If you think No-mega is more likely than Omega, then you shouldn’t be that kind of person either. So it still doesn’t distinguish between the two questions.
...why should you also consider that possibility?
Because if that possibility exists, you should not necessarily precommit to cooperate with Omega, since that risks being punished by No-mega. In a universe of No-megas, precommiting to cooperate with Omega loses. This seems to me to create a distinction between the questions “what would you do upon encountering Omega?” and “what will you now precommit to doing upon encountering Omega?”
I suppose my real objection is that some people seem to have concluded in this thread that the correct thing to do is to, in advance, make some blanket precommitment to do the equivalent of cooperating with Omega should they ever find themselves in any similar problem. But I feel like these people have implicitly made some assumptions about what kind of Omega-like entities they are likely to encounter: for instance that they are much more likely to encounter Omega than No-mega.
But No-mega also punishes people who didn’t precommit but would have chosen to cooperate after meeting Omega. If you think No-mega is more likely than Omega, then you shouldn’t be that kind of person either. So it still doesn’t distinguish between the two questions.