Talking about someone's track record of predictions is not an ad hominem, in the context of evaluating their credibility with respect to the subject of those predictions.
An ad hominem attack occurs when someone attacks the person making the argument rather than addressing the argument itself. For example, saying "You're always wrong, so you're wrong about this too" without addressing the current claim would be ad hominem.
That's exactly what the person I responded to was doing.
> Take a look at videos on YouTube by ThunderF00t. SpaceX is pretty problematic.
Response:
> Thunderf00t has basically 0 credibility when it comes to SpaceX. He predicted that starlink couldn't ever work, for example. In fact, he even thought that this landing would fail.
You’re claiming Thunderf00t is a good resource on SpaceX. The response gave examples of how he’s been consistently wrong.
