Enormity doesn't mean really enormous. It means incredibly horrible.
The problem with enormity in marketing is that it doesn't work. Enormity should pull at our heartstrings, but it usually shuts us down.
Show us too many sick kids, unfair imprisonments or burned bodies and you won't get a bigger donation, you'll just get averted eyes.
If you've got a small, fixable problem, people will rush to help, because people like to be on the winning side, take credit and do something that worked. If you've got a generational problem, something that is going to take herculean effort and even then probably won't pan out, we're going to move on in search of something smaller.
Not fair, but true.