@mathanxiety You haven't exactly challenged any of my points.
The 'you' refers to whoever organises, it doesn't really matter whether it's the honoree or not. Especially as in the context of this thread it's the OP who wants it. It's one thing to have people throw you a shower of their own volition. It's another to want one, 'get people' to organise it which in essence is the same thing as you organising it yourself, as 'you' are the driving force.
You and I also have different expectations of our guests. When I throw a party I don't expect gifts. Their presence is enough and I want them to enjoy themselves. I'd expect similar for a party thrown in my honour. I don't need to to do any 'gift giving dance' I just state upfront that it's not required. You, however see it as 'horribly rude' for guests to turn up without a gift so our values clearly differ.
Finally I don't think my colleagues lack manners at all. When you work in a large team some groups of people are naturally closer than others. Unless you want to stick someone with the 'office housework' of recording people's life events and organising things (usually left to women... lots of studies on this) you can't claim that person A lacks manners because they organised something for their workplace bestie, person B, but not for person C whom they see at weekly team meetings but don't otherwise know.
At the end of the day as I stated earlier I'm not against a party. 'Cringe' games, whatever, fine. It's the expectation of gifts. If people acknowledge that and either state no gifts or something simple then logically speaking this issue is solved. However most 'baby showers' I've been invited to are not like that - there's no guidance, the gifts have varied and there has been a lot of upset. The people who tend to 'have them thrown' have. a certain personality type shall we say. Even if I didn't manage to attend I certainly heard all about it!
Those what want a party tend to call it something else and those are actually fun, with consideration for guests. Happy to attend anytime.