You can look at inspiration in one of two ways.
The first way is to see it as a feel-good message that basically says “Don’t think about any negative stuff if it makes you feel bad. Just focus on the positive and all the bad stuff will go away.”
The second way is to see it as a hard-nosed dosage of realism that says “No matter how bad it gets, we will never create any progress unless we find a way to translate our legitimate experience of anger into a positive ideal that we can feel motivated about acting on.”
I prefer the second way.