I totally agree.Your "suicide cord" would be a major danger if someone unplugs it (accidentally or otherwise), since the prongs would be live. The bigger issue, as others said, is that you would be placing linemen and the general public in danger by backfeeding the utility transformer. This is what you get on the high voltage side of a utility transformer when you backfeed it:
Because it is both illegal and stupid to connect a generator as you describe, you could be charged with manslaughter (potentially even murder, depending on the jurisdiction) if someone were killed as a result. You would also be civilly liable for any injuries of damages that result.
Just get an interlock.