That's an acceptable thing to do for catharsis, but not so much fun when your diary entry lands on hacker news.
The problem is that the person reading the blog (like me), reads it in our own voice and the division between "working to cure cancer" vs "curing cancer" seems to be one of consequence not intention or effort (merely "wanting to" is weird).
Because being congratulated for trying-so-hard sucks, when you know you are failing instead. So much harder on your ego to tell people "I can't do this", while they're patting your back for almost doing it. Or maybe, I read it like that because as a parent of a newborn + working from home, I'm going through this somewhat.
I read the "morally incompetent" as just short hand for "not being honest about current state of mind".
But y'know what, that sort of honesty can kill things because everyone who succeeded knows the dark times where everything seems hopeless until something out of your control drops in to give you a push forward. To broadcast "I don't have it in me" usually prevents such serendipity.