Of course there are shades of gray. Some readers will capitulate while others don’t. Some readers will come that much closer to taking your advice and maybe do something about it at some future date. All this will be taken into account at grading time.
Also taken into consideration (in a very big way) are the persuasive techniques you employed in your paper. If you used them well, that’s a big plus.
Finally, your choice of topics and purposes will influence your ability to persuade. You don’t necessarily get extra points for choosing to try knocking down difficult inherent barriers. You might get a little mercy for using values or a really great organization, but you’re best off if you choose a doable purpose from the outset.