Unfortunately, there really are dedicated and heavy operations by government organizations and corporations to try and sabotage debate. These operations are well recorded, especially corporations such as Microsoft and Samsung who are well known for it. It's just a fact of online forums. Of course, it's also a fact that a lot of people obviously hold diverse opinions. It is just plain impossible to be able to reliably tell the difference between astroturfing, trolling and genuine opinions.

Honestly, the best solution is simply to state your argument and leave as back and forth debating is generally useless. This applies in both the case where you are arguing against someone who appears to be astroturfing and where you are in the position of having an unpopular opinion. You're just wasting both your time and others with pointless arguments. HN is pretty good on this point by having that 'deep thread cooldown'.