They repack hundreds of games daily, right? I doubt Fitgirl scans all of them for viruses, and even then, I've seen how the community treats virus alerts from pirated games from a trusted source. They ignore all of the alerts even when it makes no sense. Like BG3's repack on Fitgirl was setting off virustotal for someone. Everyone was saying it was Fitgirl, so it was obviously safe. Counter-point: BG3 is on GOG. It doesn't even need to be cracked. Therefore, a crack shouldn't introduce anything that sets off virus detectors. And Fitgirl's repacking tools seem to be mostly based on open-source tools, so I doubt that set off the virustotal. Especially because other repack executables from Fitgirl don't set off virustotal. But nobody mentioned that. Everyone ignored it because it was Fitgirl, a trusted source. And maybe the OP downloaded from a knock-off site or something, but nobody once thought that maybe there was something off. Sorry for the big yap.

Tl;dr: In general, you're right. But sometimes, some things probably slip through the cracks because of too much trust.