I hear you. It’s a pain. I wish FCPX didn’t try to force this. My workflow is to copy all media from the cards to a hard drive first and then import to FCPX by selecting the top folder and making sure ‘leave media in place’ is selected. If you make the mistake of opening the folder and ‘looking inside’ – FCPX will think it’s a media card and will force to import the media. The workflow to avoid that is to close FCPX and once re-opened, import the whole folder without opening it first.
Honestly, I wish Apple stopped treating us like children or idiots and allowed us to select what we want to do with the media. I wouldn’t edit from a camera card but if someone wants to (news), let them for crying out loud.