You're free to say and believe whatever you like, @tvulgaris. Anyone can say the dark energy hypothesis is correct or incorrect even while entirely ignorant of what the hypothesis claims and the mathematics underlying it, but this isn't a stance a rational individual would take.
The question a rational person would ask is: "Am I knowledgeable enough about cosmology, and/or physics, and/or astronomy to understand the dark energy hypothesis, claim it's bullshit, and then then provide a plausible alternative, with new evidence, that fits the facts as we currently know and understand them but negates some or all of the currently-accepted dark energy hypothesis?"
If the answer to that question is yes, then the Nobel committee would likely want a word with you, and you could find yourself a great deal wealthier and more famous in the coming decade.
If the answer to that question is no, it's probably best to admit you don't know enough about the matter to warrant a concrete belief one way or another, and that people who work in those fields are better-suited to work at determining the validity of the hypothesis.
Is dark matter bullshit? I don't know, chances are you don't either, and there's nothing wrong with not forming an opinion on the matter if there is insufficient evidence to do so. :)
I certainly don't, which was much my point- but it was the process of hypothesis itself I wanted to juxtapose to the experience of religious faith- dark energy was a useful example as the math underpinning it ISN'T empirical evidence. There's absolutely nothing empirical supporting the hypothesis YET- which a doctrinaire mind can quickly construe as bullshit. My question was leading.
Maybe you haven't run into the very many people (there's a lot in my age cohort) who label themselves "atheists" but for whatever personal reason have taken on an anti-theistic jihad, every bit as irrational as the most stupidly blinded fundamentalist- I suppose Doc has, I know I have. This is not to generalize, because I have atheist (or at least very well-read agnostic) friends I'll spar with, or just hang out with, and this is no cause for animosity.
I'll take it "on faith" those anti-theists are the people he's addressing...