No, I agree it's generally a worthwhile skill. I objected to the generalization from insufficient evidence, when additional evidence was readily available.

It's an online discussion. There a bunch of information that might not be shared because it's too private to be shared online. I certainly wouldn't share all information about a romantic interaction on LW. But I might share enough information to ask an interesting question.

I do consider this case to be an interesting question. I like it when people discuss abstract principles like rational decision making via Bayes theorem based on practical real life example instead of only taking far out thought experiments.

I'm arguing that it was the wrong move in this case, and hurt him and others.

If I'm understanding you right, you don't even know the individual in question. People drop out of Phd programs all the time. I don't think you can say whether or not they have good reasons for doing so without investigating the case on an individual basis.