[isostatic]

This type of thing was always inevitable from the day top-posting became acceptable (and pretty much mandated by the email clients)

Before then, you would reply to points in line and trim unneeded information. The entire conversation wasn't bolted on to be ignored by 99% of people.

[oblio]

It would be harder, but still possible. The "trimmer" could keep the offensive bits in, causing even more damage because of the higher visibility.

Just don't write offensive stuff :)