Parables are the lowest form of argument. A valuable principle should be stated directly. It is absolutely worth making the caveats explicit, because there will always be people who try to enforce the exact letter of the principle.

Implicit in my comment was that it would be strange/tiresome to present it as a solid argument.

I more or less don't believe that principles are actually possible to act on in a principled manner. If everyone all at once took a deep breath and started calling the things they call principles ideals, we could probably avoid a lot of bad discussions (because implicit in that labeling is the observation that compromise sometimes happens).