I understand, and I don't want to see ads in such contexts either. But "nobody believes this" is of course a personal attack, and "you don't have the power to [do what you just said you will do]" is pretty aggressive too.
The impulse to hit back against what is perceived as a "transparently dishonest corporate actor" is natural and human. I feel it also, and in fact my first response when I read such comments is always an adrenaline surge and the peculiar pleasure-hit of righteous indignation. So yes, I know where these feelings are coming from; we all do.
The problem is that in the HN context, (1) there is a human being at the other end of the account being attacked, and (2) there are orders of magnitude more attackers. In practice, this can easily turn into a mob dynamic and in fact a mass beating, if a virtual one. That's bad in its own right and bad for the community here.
Edit - past explanations in case relevant:
https://news.ycombinator.com/item?id=28821698
https://news.ycombinator.com/item?id=28647036
more at https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que...