Let's talk about middle ground. Take my example, I don't like people sitting on the fence (atleast for steemit) so I don't upvote them. Downvoting them is a different story for me. So no upvote is also war for you? Or you can conclude it as MY STAKE MY CHOICE? If yes, then downvoters also exercise their downvoting rights. To them it's just MY STAKE MY CHOICE matter.
I hope you can understand my pov too.
If you think something is not worth an upvote, then don't upvote it. Seems totally fine to me. If you downvote someone solely because they post somewhere else, then you actively discourage them to post here. At least that's how I see it.
In regards to "my stake, my choice" - absolutely. We want to have and keep our choice of what to do with our stake. I guess the question is more about how we decide to exercise our choice that would be more beneficial.