Can you imagine using floppies today? You wouldn't be able to fit anything on them. A single smartphone photo would already be too big. They were already doomed, Apple just happened to be the first one to stop shipping them.
Contrast this to the ubiquitous headphone jack. It still works great. It does exactly what we need it to. It does its job as well in 2016 as it did when it was created in 1964.
With floppies, Apple saw the writing on the wall and moved faster than other companies were willing to. If they kill the headphone jack, they will be trying to force a switch that otherwise wouldn't happen. Data keeps on growing seemingly without limit, but audio hasn't changed in decades.