you're assuming a dichotomy was presented. Again, what does one person putting forth extra of their funds do in the big picture?
Concerns of virtue signaling? The ramifications of what he is proposing is that if he gets his wish, he (and others like him) have their taxes go up. He's coming out in support of policies already being discussed (and attempting to persuade other politicians to also champion those policies). This isn't changing one's profile picture in support of the cause of the moment.