A rapid or explosive decompression is an extremely violent event producing large forces due to the large amount of potential energy contained within the pressurized cabin air, which is converted into kinetic energy as soon as the pressure vessel fails.
Although seats are now better secured and won't come loose, unsecured humans (especially close to the hole) absolutely will be swept away. See my article on United 811, in which a passenger was ripped from seat 9F despite that seat remaining attached to the aircraft, and in which a plate from the galley was drawn toward the hole with such force that it became embedded in the cabin wall.
In the case of the Comet, the accident report likened the power of the decompression to that of a 500-pound bomb.
As another mathematical example, investigators on the case of British Airways flight 5390, in which a detached windscreen caused the captain to be thrown part way out of the aircraft, calculated that the force acting upon him during the 1.5-second decompression was around 5,500 pounds.