These two things can both be true. As you say, assigning blame primarily to citizens is just incorrect - corporations/governments have the most direct effect on the problem. At the same time, suggesting that the actions of citizens are meaningless until corporations/governments act is demoralizing and obscures people's power and agency. Given that most of us are ordinary citizens, shouldn't we use the levers available to us, and encourage others to do the same? For example, voting, advocacy, reducing consumption, etc.