Not really. It's not the best source by any stretch, in fact, it's probably a particularly bad source if what you're looking for is unbiased, fact-based, information.
If there were a source that was called "forum.anti-opencarry.org/forums/Why-Not-To-Open-Carry", it would probably be an equally bad place to find unbiased, fact-based, information about open carrying.
For unbiased, purely factual information, it's usually a bad idea to go to either a proponent or an opponent of the issue at hand, because both of them are almost certainly biased.
The reality is that if thugs see you OC'ing before they actually commit their crime they won't commit the crime at all and so you won't be shot.
We know this isn't always true because it is not uncommon for crimes to be committed in the presence of openly armed security guards. Said another way, it is not uncommon for openly armed persons to be shot as a prelude to a crime that would otherwise be committed in their presence.
You also mentioned that you knew of a couple of cases where persons openly wearing firearms were attacked for their firearm. That also clearly indicates that open carry isn't a guarantee of deterrence.
It is true that openly carried firearms sometimes, maybe even most times, deter crime, but it's clearly false to claim or imply that they always deter crime. That means that it's also clearly false to claim or imply that there's no need to worry about the possibiity that a determined criminal might decide to proceed anyway or about what reasonable/logical course of action a determined criminal might pursue if he decides to proceed with the crime.
I believe this has been reported all of 2 times in the last 20 years in the US to non-police OC'ers. However, you can't compare those incidents to "normal" OC as I believe in both cases the person had been a prior victim of the thugs that stole their gun. In other words, they were already known to be an easy mark and having a gun didn't change that in the minds of the thugs that already knew them. It would have been entirely different with someone the thugs didn't know.
First of all, you know
of 2 reports. That doesn't mean that it has only been reported 2 times--it just means that those are the only two reports you know about. And even if we accept for the sake of argument that it really has only been reported 2 times, that wouldn't mean it had only happened 2 times.
This particular argument really irritates me because it used to be commonly claimed that it had NEVER happened and that, as a consequence it wasn't something anybody ever needed to worry about. I thought that was highly unlikely, so I spent a few minutes searching on the internet and, not surprisingly, I found a case where it had actually happened. Since then, other examples have been found. It does happen, it has happened and it will almost certainly happen again. Is it likely? Nope, not in my opinion, but that's not the same as saying it's absolutely not something to be concerned about at all.
Second, even if there weren't any known reports, that still wouldn't mean it hasn't happened and, more importantly, it wouldn't mean it couldn't happen.
Third, it's critical to understand that since OC isn't common, ANY type of reported event involving OC is also going to be fairly uncommon. The paucity of reported incidents involving OC'ers attacked for their guns can not be properly interpreted without statistics to indicate what percentage of citizens in that area carry openly.
As an example, suppose that there were only 4 smokers in the entire world. One might, in that hypothetical world, argue that smoking was quite safe because there were only 2 reports of people dying of lung cancer from smoking. The problem is that in our hypothetical world containing only 4 smokers that amounts to HALF the smokers dying from lung cancer. Clearly smoking would be very dangerous in that situation, but if one didn't know that there are only 4 smokers to begin with, the initial claim that only 2 deaths had resulted would give a totally incorrect impression.
Similarly, if it happened to be true that in the area where one of these incidents took place, there are only 10 people who frequently open carry, that would mean the chances of being attacked for your gun if you open carry in that area would be something like 1 chance in 10. Certainly a VERY different picture than the one painted by saying that only one incident has been reported in the area.
You can find the rest of the rebuttals on the forums linked above.
I hate to say it, but most of the "rebuttals" are not "rebuttals" at all. What they are is generally poor attempts to make light of or dismiss real concerns in support of the skewed perception of many OC proponents that OC has no disadvantages.
I generally try to avoid this topic because it's such a can of worms, but the reality is that there ARE disadvantages to OC, just as there are disadvantages to CC. I do get tired of seeing folks on either side of this argument try to sweep things under the rug so that they can continue pretending that their preferred approach is better in every way than the other guy's.
The fact is that both approaches have advantages and disadvantages. OC makes sense in some situations but not in all situations. CC makes sense in some situations but is inferior to OC in other situations.