The point is that there are a multitude of various theories proposed per year. The fact is that the researchers can't drop everything and feign interest in and investigate every one of those theories.
I don't know if this is going to help but I am going to narrate a personal experience as a student ...
I was in one of our college professors' at the end of my semester to discuss some personal matter that would impact upcoming semester. Since there was another gentleman that was needed for discussion, I had to wait there ...
The professor continued his discussion about the fate of a student who had appealed to committee since he felt he did not deserve the marks he got.
The professor's argument was that the student had not attempted the problem in the same manner as was prescribed in the textbook, but used a completely new approach. He said, "I have read, re-read his answer paper till 2 am and seen all standard approaches and I am not able to understand how we came up with this approach. I think this approach is worthy of IEEE publication to share with larger community. We are debating if his case should be reconsidered, but I would say he is worthy of emulation". With something like that he rested his case.
That was such an humbling experience and till today I try my best to take lessons from that incident. This is what I would expect from a seasoned professional.
One of the Neuro Dr. said he does not see a single Neuro in Canada believing in CCSVI theory. What could be the reason for that? Not any of them have offered counter theory. If they had so much concern for MS patients (as they claim), they would do this. If Mark-thehoax-freedman was to do this, he would be a hero.
Lyon, I do agree when you say that what a researcher investigates is his own decision. But these are people who are "foremost MS experts" and people who have spent almost all their life studying MS.