Signal, Whatsapp, and iMessage threatening to leave the UK over this bill indicates to me that the bill is unreasonable. However, Meredith Whittaker did a very poor job of demonstrating that during this debate.
On top of all of that, who wants to defend child pornographers? I can see why a person wouldn't even try to engage in that back and forth. There's just no way you come out on top, because basically your side of the argument would have to come down to "Everyone has something to hide, and we should recognize and protect that." It just doesn't _sound_ good.
What is "child pornographer" btw? Is it the one who produces? Is it the one who distributes? Sharing CP != child abuse. Viewing CP != child abuse. Storing CP != child abuse. I want to defend CP viewers. Children can suffer during production (but not always: teenagers can film themselves, for example, i.e. make home videos just like adults). But no one suffers directly during the storage, viewing and distribution of files.