I think it's a legitimate question ... how censorship resistant is steem at the end of the day?

Whales defines what is to be shown on the front page, the "steem middle class" has very little power to decide on that - but not being promoted to the front page is not the same as being censored.

Steemit, Inc has the power to hide things from their Web UI, which they will probably do if they get a court order. Other providers are free to set up altnernative web pages or software applications to access the blockchain. Does there exist any alternative steem browsers? If they are easily accessible, I wouldn't call it "censorship", the content hasn't been removed.

But ... please do have a look at https://github.com/steemit/steem/blob/master/LICENSE.md ... there is one big point of centralization there. Steemit, Inc is defining what is the valid blockchain, no other forks allowed, software is not free to reuse on other blockchain projects.

Steemit, Inc is under US jurisdiction, meaning that if the US government says "jump" ... (well, I suppose a court order would be needed) ... then Steemit, Inc has to jump. They do have the power to censor content through a hard fork of the blockchain. Those sticking their guns to "freedom of speech" will not have the juridical right to do a "steem uncensored" hard fork.