I like your enumerated list of what could be wrong with that neurologist's line of thinking. It captures my anger at the narrowmindedness of some people who some of the public considers to have the last word on research.
My sister-in-law's dentist told her not to get her hopes up about this new theory and so she's a little less excited about it now. This really gets under my skin. It's her brother, my husband, who was diagnosed with PPMS 12 years ago. I have a PhD in chemistry and worked as a research scientist for 10 years, have read Zamboni's papers (only started since the W5 special however), and have told her that this theory is an incredible change of thinking, looks really promising, and considering the potential benefit/risk, we should (and are) actively pursuing a treatment. My background doesn't give me the backing to say this is bunk - there have been no credible studies brought foreward to disprove it, so I remain hopeful.
People who are getting "advice" from their dentists, pharmacists, and even MDs, along the lines of "this theory will never work" should ask the person if they've actually read the papers. Don't forget that they have undergraduate degrees in which they learned scientific principles in order to carry on their profession. They are not necessarily any more up-to-date in this area than you are.
I do expect more from specialists, such as neurologists, who have a responsibility to be measured and practical in their responses to patients. There is no evidence out there to support the proposition that treating CCSVI will not relieve the symptoms of any MS patient. In fact, the published scientific data and the anecdotal reports from people on this board (which seem very credible and unsensationalized) should give every reason to support aggressive research in this area.
Anyway, that's my rant for the day - if any one reads this, thanks for listening. I feel better now.