People do it because they effectively have a choice between accepting spying or not playing at all; we don't have a perfect market with infinite number of choices, there are just few major game makers and all of them want to have tracking.

In nothing changes then tomorrow companies might be copying your whole disk content to their servers. This way they would earn more profit than without disk image analysis.

I don't know, it might be a contributing factor for piracy. They should value their paying customers more.

If its free I'm the product: fine. I can live with that. But if I pay for something I don't want spyware and targeted ads.

What's your point ? Buying the next game doesn't prove people agree.