It will not affect only 6 people.

That is just the number of people who have forks that we know about and even those who do not have forks but maintain a copy (for whatever reason) of the main branch will be affected: they will have to reset their branch or do some other malarkey to get this new "improved" history. This will be a much bigger group of people and also potentially software solutions that are mirroring the repo for one reason or another.

That's one of the prices you pay (or I would say benefit) for having a decentralized version control system: it makes it hard to rewrite (supposedly "improve") history.