Isn’t the usual advice to turn off your main breaker? Both to protect a lineworker and to avoid stalling your generator by trying to power up the neighbourhood?
Keep in mind that backfeeding your house won't actually work unless you disconnect from the grid. Your little generator cannot power the whole grid. You'll pop a breaker immediately. So even a total idiot isn't going to electrify the neighborhood (though they could cause serious momentary risk).
I know a couple people who use this approach. They're some of the most electrically savvy people I know. I don't get worked up about it.
Better advice is to use a proper inlet, with either a real transfer switch, or a mechanical lockout if allowed in your jurisdiction.
If you're using a cord like this, you almost certainly don't have anything but your brain preventing you from using it wrong. Brains aren't always enough.