If you make a cable to plug a 15A outlet in your home into a 15A outlet on the generator, then hopefully the generator has its own breaker that would trip if too much current was drawn.
If you plug your house directly into a 40A outlet (which has a different shape) then, yeah, you're screwed.
If you plug your generator directly into a dryer/oven outlet, it should be on a dedicated branch circuit, and everything else you load in the house will actually have two breakers between it and the generator... one for the branch you're feeding from to the bus, and one from the bus to each branch circuit. And the generator probably has a third.
The only real difference between this setup and a proper generator hookup is a mechanical interlock so that the main and feeder branch breakers can't be on at the same time, and the gender of the generator hookup outlet.
If you plug your house directly into a 40A outlet (which has a different shape) then, yeah, you're screwed.