I admit that I do sometimes save scum for 2 reasons:

1) To see all the possible outcomes of an event --- Like the abandoned shipyard event, instead of getting ships or it breaking outright... maybe there's a rare chance for a tech? Or fixing the shipyard? Maybe other stuff? I'm very curious about that sort of thing.

2) If I'm playing a relaxed roleplay-based game, I will save scum if I think something that happened to me was absolutely not fair (by my definition) since I'm playing for fun, not to min-max or stuff like that.

An early-game example could be warping to a system to explore and the fleet/science ship happens to land EXACTLY on a 2 separate 250 strength crystals or close enough that they are at 95% warpout before they get into combat range... realistically I'd like them to continue warping out but no, now they're stuff in an un-winnable engagement for 2 weeks or something, even roleplay wise it wouldn't make sense to me.

Generally speaking I don't save scum often, it's fairly rare for me to do it (even for the events, ones I'm familiar with) and it's usually only in the early game, the first 20 years or so, after that I take the good with the bad, no matter how bad it is.