Logic:

Your story is this:

I took my son to a doctor, because he had trouble breathing. After the medical treatment my son could breath freely again.

Thus, you left out crucial details about how things came together.

1. Justin Sun not only announced some marketing things for Steemit! (Not Steem, Steemit!). But he also announced things like token-swap and taking all Steem dapps to tron smart contracts.

2. Witnesses tried to contact Steemit to get in contact and get relevant information.

3. Only then the softfork was decided.

4. Community could've voted out these witnesses if they were against the softfork (this did not happen, on contrary, witnesses against the softfork were voted out).

5. "External Security Experts". You mean Ned?

Edit: 6)

The witnesses ability to freeze someone's account over night without even talking to the community (which elects them and gives them their power to do so in the first place) clearly is a feature that should not exist in a decentralized blockchain.

It seems you got no idea about how DPoS blockchains work. Any consensus node can decide to "block certain transactions" at will in any blockchain (same applies to PoS and PoW).

Thus, if in DPoS a super majority blocks certain transactions to be included in blocks, the stake is practically frozen. This cannot not exist.

Edit2:

If in Bitcoin a few of the biggest mining pools decided certain transactions to be invalid from now on this would also lead to the same outcome.