The reason they berate them is that people frequently say "If everyone does a little, we'll get a lot done.", and then do a little and stop, congratulating them

The reason they berate them is that people frequently say "If everyone does a little, we'll get a lot done.", and then do a little and stop, congratulating themselves about what they've done. In order to affect real change, a lot of people need to do a lot. Focusing on and performing little actions distracts from doing the the big things that actually make a noticeable difference.