A negative reaction to a mediated communication is described as

A negative reaction to a mediated communication is described as flak.

Flak is critical feedback, complaints or pressure aimed at media content by audiences or interested parties.

Fragmented feedback would mean scattered partial responses, not specifically a hostile reaction.

Passive response describes indifference or no reply, the opposite of an active negative reaction.

Non-conformity names departure from norms rather than a reaction directed at a media message.

Flak acts as a disciplining response that media producers must anticipate.