Surely not everyone thinks it's "amazing"

I assume they would be removed if someone spoke up though

Because they would of been told what to say by production, or be removed/banned.

Because they were told not to

why aren't the audience questioning why they are even there

They're muzzled where certain subjects are concerned.

It's also cringeworthy when Rylan asks panellists or guests anything about 'this year's BB' they are all obliged to say how great it is or that it's the best it's ever been.

I agree - the panel and the audience are towing the party line, and once again, assuming the viewers are too stupid to notice