It could be that Icke throws in Reptilian stuff (just one example) to make himself less of a target for elimination. It allows his enemies to discredit him in the media, thus eliminating him as a true threat. Basically, he gives them an 'easy out'. But meanwhile, he also keeps pumping out other great information on what is really going on (Agenda 21, etc, etc) that can be documented. And he knows that people who follow him closely will be getting the key information, and will know what to accept and what to dismiss. That's probably why he has lasted so long. It's a brilliant strategy.
But then again. Maybe all the reptilian stuff is true. Either way, Icke works his arse off to expose these bastards.