My experience is that people attack experts incessantly when it conflicts with their politics. (Think: Anti-vaxxers attacking the medical system). In my experience they may raise good points, but those are usually tangential to the matter at hand.

WRT this specific expert group, is there something wrong with them? I haven't heard such but am willing to be educated.

Disillusionment is easy when one accepts sweeping generalities, but much harder when dealing with specifics. Again, only my experience, but "They are all (something)" only lasts until you take a closer look.