You made a fair point, and yes there are likely spammers and if not actual spammers, there are trolls who just want to argue.
The part you said about IP addresses being the same. I have no way of knowing how many people here have multiple accounts but there are some who do. Not long ago I made a comment to someone behind the RIU curtain about a couple major thorns in my side and their IP address was checked and were the same and the accounts/address were blocked.
It happens on every site. Some time back when there was a flood of anti-Attitude threads that were all started by members with post counts of around 15 or so and then a second member with roughly the same post count would chime in and back them up I posted a message here from another site I hang out on. The very same thing was going on there, and on most of these sites at the same time, and a mod wrote a message that said they checked the anti-Attitude thread starters IP address and the one who a few messages later chimed in agreeing and then they tag-teamed in the thread and they were the same and they were blocked.
It happens, it is unavoidable, it is a pain in the butt, but people will do it, and you might be right that at least some involved in the Dr. Greenthumbs thing could be spammers.
But then when you put together all the pieces of evidence, from various people who if anyone would know the truth about G13, what they have said and add in things like the original description of G13 that few if any today ever read or remember and how totally different it was from what Dr. Greenthumb's description is and the every evolving storyline from Dr. Greenthumb as to the origin of his strain, and any reasonable person would have to have extremely serious doubts as to it's authenticity.
Then add what happened to people like me who were sold fake Acapulco Gold seeds from his Heritage Line, that did not survive long, likely because it was all fake, and again, any reasonable person would have to have extremely serious doubts as to the authenticity of Dr. Greenthumb's claimed too be G13.
He has sold fake versions of famous name strains in the past. There is no questioning that. Now he allegedly has a strain that the people who do, or at least should, know the most about it say it died off, or that what he has is not pure and at the very best a hybrid or maybe, but doubtfully, an F2 or an F3 or something. He has an evolving story and while people claim certain people have verified it, even each version of it, you cannot find anything from those who are claimed to verify it, and if anything what you find from them discredits it. Then you go back to how a plant what when pure and being grown and used in crosses had a description that is about as opposite as any description could ever possibly be from Dr. Greenthumb's description of his strain, and once again, any rational, logical, reasonable non-biased, open minded person would have to have extremely serious doubts as to it being what it is claimed to be.
So sure, maybe spammers are involved and they are doing their best to keep the subject alive and to get the word out to as many people as possible, and maybe their motives are not fact based and they may not care one way or the other and just have some totally different agenda, but when you look at things under a microscope and do so totally objectively, it is impossible for any unbiased person to think anything other than there are very valid reasons to question the validity of the strain and no number of possible spammers and or trolls involved will ever be able to alter that fact.