It's one thing for you to put a banner up on your web page, which I will see when I visit you. I can just choose not to visit, if I don't want to see your message.

It's another thing for you to put a banner inside my computer, on the software I use to manage my own data: that ought to be a tool I use for my own purposes, and not a place for you to do what you want.

A tool which starts acting as an agent for its developers, not as an agent for me, is not a tool I want to continue using.

The same way you can decide to not visit a website, you can decide to not use LibreOffice.

I think it makes sense, how else are they supposed to fundraise and develop the features that makes the software useful to manage your own data?