Politicians just aren’t willing to get involved with the feasibility and the nitty gritty of what it would mean to break encryption. Or maybe they aren’t technically minded enough.
They ask for what seems like a reasonable request - let us read terrorists’ emails if we have a warrant, without affecting everyone else. Anyone non-technical would probably vote for this no problem.
They don’t understand it’s just not possible without creating some impossible to keep secret master key. I guess politicians are used to giving other people problems and just expecting them to figure it out.