What if the US govt really wanted to censor Steem?

This is a very hypothetical situation ... but I would like to lift it anyway. (Well, I already sort of tried in https://steemit.com/steemit/@tobixen/is-the-steem-blockchain-100-censorship-resistant but I'm not sure my point got through, so this is the teaspoon post).

A blockchain is supposed to be immutable - that's one of the basic features of a blockchain, when something is written there it stays. Child porn ... blatant copyright violations ... detailed instructions on how to execute terrorist attacks ... write it to the steem blockchain, and it stays, it's impossible to remove it ... or so goes the theory. The bitcoin blockchain is done immutable by applying "proof of work" . History rewrites or a hostile takover of the network itself would require so much computing power that it's considered impossible. In Steem, the immutability is supposed to be enforced by the witnesses. at least 50 independent witnesses would have to collude to be able to rewrite history or do a hostile takeover of the network ... or so goes the theory ... and the witnesses are democratically elected.

Then comes the software license and destroys everything. https://github.com/steemit/steem/blob/master/LICENSE.md - point 4 and 5 there, I think they should not be acceptable. As I read it, nevermind the witnesses ... Steem, Inc has the power to define what is the correct Steem blockchain. Hardforks not approved by Steem, Inc is not allowed. It's also not allowed to create a new and independent blockchain based on the same software.

So, hypothetically, someone out there slaps a DMCA notice on Steemit, Inc. Unfortunately Steemit is under US jurisdiction, so they have to respect DMCA notices. Steemit Inc removes said content from the web page to protect themselves from a lawsuit - but the content is not really censored, because it's still available on the blockchain.

Next, someone complains even louder, the Steem blockchain needs to be done DMCA complient ... or else! So Steemit, Inc reluctantly releases a new version of the software, operating with a non-immutable blockchain, where a DMCA complaint will cause content to be ripped out of the blockchain and deleted from all nodes.

That would be quite silly and stupid ... so naturally the witnesses would reject it. That should have been the end of the story, the blockchain has successfully defended itself against a censorship attack ... if it wasn't for the license. Now, Steemit Inc can define the broken blockchain to be the only right one, and anyone not upgrading the software to be DMCA complient version would be violating the license.

Please tell me that I'm wrong ...