Yes. If it can't remember, there won't be progress on anything.

Yes absolutely, how do you think you prevent people from ddosing and how do you think we prevent spam if not with logs?

Also I'm surprised how nobody has mentioned how important this data is for AB testing.

Perhaps "using customers as guinea pigs" is not the hill you want to die upon? A/B testing is not a good justification for data collection. It may, actually, be a good reason for condemning it.