They are just trying to pull your chain
They know they haven't got a credible argument against HLG. Steve and Robin's products are well documented in RIU; by numerous people who have tested their products... and now these products are well-known as products that work, supported by guys you can trust, despite the naysayers trying to say otherwise lol, And hence why they cannot answer questions or post evidence to the contrary.
They are simply taking their frustration out on people who have
"Bought" HLG products/Know that they work/and now support the company. they are stuck in their worldview, which is sadly based on opinions rather than facts and evidence.
My advice is, do not waste time getting caught up in arguments with such folk, because no matter how much evidence you present, once they have formed an opinion logic tends to fly out of the window