It just feels wrong to force push, destroying stuff that used to be there.
And I don't have the time or energy to bisect through my shitty PR commits and combine them into something clean looking - I can just squash instead.
Things that aren't referenced by anything anymore will eventually get garbage collected and actually destroyed, but you can just keep a reference somewhere to prevent that from happening if you need. Or even disable garbage collection completely.
Looks like people's fears about git come just from not knowing what it does.