Not as much "dogma of the scientific community" as chronic, repetitive, negative experience for several hundreds of years.
Now the scientists are simply saying:
"We've heard all this before over hundreds of years, tried it and tested it so many times we've lost count and it was consistently proven bogus. Show us something we haven't seen before in a different disguise. Such claims simply aren't sufficient anymore to warrant serious consideration without new evidence."
It's that simple.
Now, when a person is intelligent enough to see the falsity of it all, he's labelled a closed minded dogmatist by those either obsessed with a pseudo-science profit making agenda or those who are just plain fools and easily duped.
Skeptics simply want evidence that is proportional to the profound magnitude of the claim.
There's nothing wrong with a closed mind - IF your argument is correct and you can prove it. There's the catch.
The bottom line is:
No 'law' of nature has yet been observed to provided a free lunch. Why simply assume otherwise without any apparent evidence?
The biggest barrier to 'free' energy is NOT skepticism, but the laws of nature itself.