Yes, most are just fan clubs and will not stand for anything negative, that can also happen on some of the cruise critic threads for the actual cruise lines or ships.
I couldn't find any discussions on any other CC thread about bed bugs, note that doesn't mean they don't exist.. So I presume it is other social media.
Firstly welcome to Cruise Critic.
Secondly, I am not sure people are slating you, and while I have been lucky enough to have never encountered them, they do exist. People have been relating their experiences and I suppose speculating on if they were bed bugs or lice.
Thirdly, I am sorry for your ordeal and subsequent humiliation.