The result of contentious hardforks is super interesting from a technical level.
A lot can go wrong and create a total clusterfuck.

But also I don't know what to tell you because this is exactly what happened.
This is how we froze the Steemit Inc ninjamine.
It happened. That is a fact. Incontestable.
So unless you have some new information as to how this happened: what I said still stands.

dropping blocks containing transactions that violate new rules...

The witnesses can drop a block for any reason they want.
There doesn't have to be a cited reason for why it's against the rules.
They just drop the block and get consensus, or don't.
The rest of the network follows that fork by default because those are the rules of consensus.
Dropped blocks are a totally normal thing and don't lead to a hardfork.

for me any change that affects previously valid blocks is a hard fork change

Only if that block was immutable.
If it's a droppable block and it gets dropped, that's not even a soft fork, let alone a hardfork.
The code to drop blocks has existed from day one by necessity.
DPOS witnesses don't need to give a reason for why they dropped a block; they just do it.
They are the ones in charge, which is the entire idea behind DPOS consensus.

This argument you're making reminds me of several downvote wars years past in which people tried to say that downvotes are committing literal violence and theft upon the 'victims'. That's not accurate, as an upvote isn't money until it pays out 7 days later. Just like a block isn't a block until it becomes immutable. A dropped block is never going to create a hardfork automatically because that would destroy the entire DPOS model. Devs would have to go back and craft that hardfork by hand and then replay the entire chain from scratch.

Yeah?