Sure, but this problem has been around for years, and HN has developed many mechanisms to deal with it. Some are obvious—if a post gets to the front page without community interest, it will quickly attract flags, and probably a lot of ornery comments too—and many more run silently beneath the surface. I think the proof is in the pudding: we don't see a lot of this. Anybody getting away with it regularly is probably being so devilishly clever as to deserve their ill-gotten gains.