> A Monte Carlo simulation that always gets the same results isn't going to be too hot.
A Monte Carlo simulation absolutely needs to be able to produce the same numbers every time if you want to have a hope of debugging it. In a release version, yes, sure. But even there, people will still have concerns about replicating other people's results, so being careful with random seeds is important.
There's a difference between "always uses the same seed" and "can be seeded for reproducibility". You probably want the latter and probably don't want the former.
A Monte Carlo simulation absolutely needs to be able to produce the same numbers every time if you want to have a hope of debugging it. In a release version, yes, sure. But even there, people will still have concerns about replicating other people's results, so being careful with random seeds is important.