You can absolutely frame enshrining privacy and punishing those who would spy on you in a populist way. The messaging writes itself. The problem is that anti-power populism is considered extremely dangerous and tamped down on far more strongly than the most virulent bigots and fascists.
Populism is how you win votes, but only one form of populism is allowed. For now, at least.
Fascism requires an authoritarian state. If you don't want the horrors of the 20th century, be it fascists with a world war, or socialism with even more deaths despite being in peacetime, you don't want authoritarianism to take hold, and you want to move power out of the state.