@quincho you've invoked a slippery slope argument. A slippery slope argument can be defeated two ways: denying the slope and saying where the slipperiness stops.

The slope denial: It's not censorship because the content is still there on the blockchain. Certain platforms will take downvotes and low reputation into consideration when they decide what to users. To claim that's censorship you'd have to make the claim that any kind of filtering is also censorship; a feed that shows only people I follow! Why that's, censoring everybody they don't follow! Yes, the people who follow make a conscious decision to follow, but they also make a conscious decision to use a particular steem interface.
If you want a version of steem that conforms to your own views on filtering then go ahead and download the code and tweak away. When you make that, I'm not convinced you'll like the creation.

The stop: Assuming I accept the slope exists, then here is how I distinguish where I personally "stop" sliding.
Posts that are self-upvote-rings are reward pool abuse in my eyes. I'm extremely reticent to opinion-flag though I have once opinion-flagged an extremely racist cartoon that provided zero context for its opinion.

I tend to agree with you that if we went around opinion flagging for mere disagreement then steem would become a much much worse place. Though, you are correct, largely it's the money that determines the "social rules" that operate here. Seems pretty libertarian live-and-let-live for the most part.