PeterM, I'll give it a shot. not sure if it's the right answer tho:
The purpose of a shower is receiving presents
The purpose of a wedding is getting married.
At a shower, presents are the reason of the event. At a wedding, gifts are there to celebrate the event.
Am I getting it right? (showers are pretty much unheard of on this side of the pond, so it's a guess)
I can see that as a decent comparison of showers vs. weddings, yeah. I do think many, many, many people would disagree with the idea that a gift isn't really required for a wedding, but I'll agree that it's not quite the same level of requirement as a shower.
The specific discussion/argument I was thinking of when I posted that was about birthday parties, actually. Specifically, the custom in some European countries for the birthday boy/girl to invite friends out to dinner to celebrate their birthday. The host would pay for the dinner and no gifts were expected. This was declared to be tacky and wrong because an important etiquette rule is to basically never deliberately draw attention to or aggrandize yourself. Which sounds great until you remember that throwing your own wedding is considered perfectly acceptable, and those are generally more self-glorifying than taking a few friends out to dinner for your birthday. No one's ever explained the dichotomy to me, but that's a completely different topic that has nothing to do with this thread so I'll shut up now.
Personally, I find nothing wrong with inviting friends out when you have a birthday without expecting presents or for them to pay for you. Especially if the birthday boy/girl is the host and paying for it. But that's not exactly the topic, of course.
Basically, giving yourself a shower is more or less the same faux pas as including registry info in a wedding invitation--you're inviting people to give you presents. This LW is incredibly disingenuous when she says she didn't expect gifts. Actually, she's flatly contradicting herself. I have little sympathy for her.