Straight forks

apparently because if you hit a bump at speed, the rake helps take the impact a bit as the forks are not hitting the bump at 90 degrees or so.

A zero rake has less of an angle so is more likely to bend back towards the frame.

That is not what would actually happen. The head tube angle will be around 73 degrees so the fork even with zero rake will still be at a forward angle. A bump would raise the fork up and away from the centre of the bike just as a raked fork would.

Your example would require a head tube angle of 90 degrees or even more!

I reckon you may be thinking too much about this one :-)