This is such a great distinction between excuse as a verb and as a noun. I love what you wrote– very thought-provoking!

When we use it as a noun, as you have done here, we are using it as justification for an action or (an in-action). The noun has a hard “s”, which makes it a bit sharper-edged and declarative and final, as if to give it emphasis, to make up for the fact that we are really hiding the truth and don’t want to talk about it. As you point out we often confuse an excuse with a good reason, but they are not at all the same thing. An excuse is a thinly-disguised way of saying we really don’t have a good reason for some act or omission and we are afraid to tell you (or even ourselves) the real reason. Excuses are really kind of dishonest. Are we lying to you, or ourselves or both? As you point out, we hate to admit something we really want to do is too hard, or too unfamiliar or we are too afraid of failure and too embarrassed to tell you (or ourselves) the real reason.

When we use it as a verb is has a softer “s” sound. It is a smoother, quieter sound for a generous act, whether I am excusing you or you are excusing me. It has a sense for forgiveness or compassion, whether it is for a friend, a stranger or even ourselves. When we come up with an excuse for our behavior, maybe we are attempting to excuse or forgive ourselves for not having a better reason for what we have done (or not done). If we were more trusting and honest with ourselves and our friends maybe we would have much less need for the noun and much more for the verb. Trust your friends. Trust yourself. No excuses!

Just a thought.