For many reasons, one being that they were injecting urls with their affiliate codes to unsuspecting users.

This was in 2020. Brendan Eich addressed this in a blogpost iirc, with a perfectly plausible explanation. It seemed like a bad/unfortunate design decision, which happens all the time in software development and not the conspiracy theory people claimed it to be. It was fixed in a matter of days.

If this is the main reason to not use Brave then I'm genuinly interested in hearing about the other reasons. I might learn something I wasn't aware of.

I don't understand all the hate Brave gets either. It passes pretty much all privacy tests ootb and I see 0 ads, on desktop and mobile. This is what actually matters to me.