organise whatever you want...
I've already stated a few times that the honoree does not organise her own baby shower (or wedding shower).
giving them a list without them even asking is presumptuous...
Registries in the US, where I believe the concept originated, always include a wide range of prices.
The idea that it's presumptuous to send an invitation with a link to a registry isn't rooted in politeness. It's rooted in a very quaint notion that money shouldnt ever be mentioned, which means money is always on people's minds, and the equally quaint idea that it's not ok to look grabby.
If you start by acknowledging, as a guest, that going to a gathering without a gift would he horribly rude, and you work backwards from there, you'll see that it's actually polite to let guests know what is needed. This saves them time and money, which is a polite way to handle the delicate question of a gift. It also gets the drama out of the whole gift giving dance and lets guests focus on the fun and the people at the party.
it all adds up...
So the organisers (again, the honoree is not the organiser) ask guests to bring a board book their own child loved or something else equally simple and inexpensive. I've been to wedding showers where the guests were asked to bring a favourite casserole or dessert recipe (photocopied or handwritten). I've been to baby showers where the gifts were pictures drawn by the guests' children, some of whom were cousins and some of whom were friends of the mother to be. These were later put in Ikea frames and used to decorate the baby's room.
Fwiw, I'm Irish and showers were never a thing in Ireland when I lived there. The office I worked in in the US was full of lovely, generous, fun loving people who liked a good party - this describes most Americans I have met.
It's a huge pity your workplace was so unpleasant and that people there were so lacking in manners.