I bought a software product for work several times. But it was not purchased in any way related to my personal Google account. Using Youtube to learn about the software has cause me to see thousands of ads for the software I had purchased several times already.
This is poor targeting (especially since it's direct response), and a lot of people I talk to get very annoyed telling me their experiences like this.
That's great for you, but is a tiny fraction of the problem being outlined. If you could say "Don't show me ads for this again", and total ads were held constant, you would not suddenly be inundated with ads you enjoy seeing. Ads are unpleasant, period. Targeted ads are no better.
This is poor targeting (especially since it's direct response), and a lot of people I talk to get very annoyed telling me their experiences like this.