In some defense of the OP, I did an online search for "If I receive an invitation to a wedding, am I required to send a gift if I don't go?", and slight variations of that statement. I looked at the first 10 results. (Sadly, neither EHell nor Miss Manners appeared on the first page of any of the searches.) Of those first 10 results, 9 stated that yes, a gift should be sent, even if one declines the invitation. The 10th stated it as a "no, but", as in "No, but you should send one anyway". I realize this is incorrect advice, but it is what is out there and what is coming up first in searches.
When I searched for "Are guests expected to give me a gift if they decline my invitation?", I did not get a direct answer to that question, but did get similar results to the previous search. With this misinformation so readily available, it isn't difficult to see how anyone could develop the idea that an invitation obligates a gift.
Also, when I re-read the original post, I did not see anything that indicated that the poster intended to use the occasion of the invitation to state their views and beliefs about weddings and gifts.