Ok we can all agree that colonialism is very bad, right? We didn't lose that knowledge somewhere in the last 100 years?
Spreading smallpox on accident because we're all immune carriers sounds like a Thing I Do Not Want To Do(tm)
Same for conquering anybody else, ever.
My inner historian wants all those cultures to stay extant and not die from the greed of some gaggle of future Ymaryn Patricians
So, you're saying we should let those cultures be undeveloped and not have any contact because we'll spread smallpox and other deadly disease?
You do realize that some other culture will eventually contact them sooner or later, probably one of the negaverse who knew that there are riches to be had in the not!America?
It's not even about conquest or colonization, just exploring and making contact.