I think it is clear that the rule of thumb for anything but the first baby shower is, big gifts and big showers are for the first baby only. I, personally, don't think it's weird to have more showers as I know many people see it as, "celebrating this new kid," and nothing more. I do think it's weird (and rude) to have showers after the first kid and expect gifts. Maybe two if it is the opposite sex, but that is still stretching it.
But besides the different gender situation that's it for baby showers. If you have one for each kid it's seen as tacky.
People traditionally give gifts at baby showers because it's a way of helping the new mom get all of the many tools a new baby needs. Things like car seats, bottles, etc., the sort of things a first time mom doesn't have and the sort of thing a second time mom should already have.
After the first, I don't think gifting anything more than a (small) toy or stuffed animal is reasonable. In this case, a handmade blanket is a big gift because of the work that goes into it.
If the couple has taste, they will specify that they do not want/need more gifts for the baby. They can do this with simple baby sprinkle. Or if they really want to discourage gifts they can do a gender reveal baby sprinkle. This is a good explanation of what a gender reveal in the context of a baby sprinkle is.
Even if the shower is for a first time mother that doesn't mean that it should be set up like a gift grab. However, just look at it as celebration for your baby in which you could receive some gifts, but also not.
I don't think the shower was ever intended for gift-grabbing.
I think it's more so of a celebration of your new arrival. You're not crowd funding your baby by having a shower, you are just celebrating in a perfectly socially accepted way, the way rich and poor people alike do.