My humble opinion is that it is OK to get paid for the same content on multiple platforms...the platforms set the rules of reward distribution...if the content is deemed worthy by whoever is in charge of distributing the rewards than you either opt-in on the platform or opt-out. For example for me it’s important to get the content to as many people as possible and cross-platform sharing is one of the ways.
I personally have been upvoting content copied from other personal blogs onto Steem when I was in charge of @sndbox-alpha. The idea behind it was that the content was still better than 95% of the shit that is being posted here every day and I might as well just support good content...The author too just wanted to share is content with audiences on other platforms...and hell it worked...i found it and curated it:)
EDIT: IF the one in charge of the "upvoting tool" has already seen the content he cna still ignore it on that one platform i guess...Not creating too much new content also minimizes information overload
Yes, I am not against it but, it is going to create some very, very interesting dynamics between users and absolutely, good content should be rewarded wherever it is. I think there are going to be lots of great opportunities for relative unknowns to actually get seen and make some decent returns. I hope I can help with them. What I am not looking forward to is the drivel of Trending in every trending section...
Gotcha...I think that the trending as we know it is purely problem of how steem works...for example narrative with its communities proly wont have any trending page whatsoever.