Their inability to handle an honest scientific debate is mostly the result of the fact that they are holding a belief system that is almost entirely based upon impotent in the lab supernatural entities, and the rest of it is pure pseudoscience on a stick. It's not exactly an "easy" belief system to publicly defend in the first place. It's not like I'm all that smart, but it's not like I really have to be either.

I think their inability to handle a real scientific debate also has to do with the fact that there's only about 8000 astrophysicists worldwide, and they're used to a classroom setting, or a work environment where nobody really questions the basic dogma. If you want to pass a class in astronomy, and you want employment in the industry, you learn to recite the mainstream dogma. You don't question their claims too much, lest the whole thing start to sound ridiculous, or you lose your job or you fail your class. It's an inbred supernatural solution oriented cult with a fear based command and control system. That heavy handed control system doesn't work well in a real debate on the internet, particularly when they try to leave the comfort of their heavy handed and heavily moderated boards.

Their lack of education in terms of any understanding of alternative ideas is also a significant problem for them in debate. Most of them still don't know much about Birkeland's work or Alfven's work or Peratt's work.
The fact that the mainstream simply ignored the role of inelastic scattering in plasma says volumes about the utterly absurd nature of their basic cosmology beliefs. Instead of embracing empirical physical solutions to observations in space based on observations from laboratory plasma experiments, they created three supernatural entities to try to "fix" their obvious 'rookie" mistake! Hoy Vey.
The whole dark matter of the gaps claim has become a *complete* fiasco after all the very expensive negative results from LHC, LUX, Pandax, the electron roundness tests, etc, etc, etc. Even though the baryonic mass estimates that were used in that now infamous 2006 lensing paper on dark matter were shown to be flawed in numerous ways, they're limited by their own dogma as to how much they can even accommodate any serious modification of the percentage of exotic matter, so they simply have to rely upon pure denial on that topic.
It's definitely not an easy time to be a public LCDM proponent.

I'd almost feel sorry for them if they weren't so draconian in their methods on their own boards. The witch trial forum (against the mainstream forum) at Cosmoquest best exemplifies their inability to handle any serious debate, and it's only going to get worse over time. They'll be burning heretics and witches for a long time because they simply refuse to embrace empirical physics, and their supernatural claims just don't make any sense.