They're nice for hobbyists because they bridge the digital<->voltage domains really easily, so you can just hook up wires to the pins and feed them into whatever you're building, rather than having to use a fancier microcontroller interface. But yeah it's getting to be more of a hassle that e.g. a typical laptop won't have one anymore.

In the past I've also used audio line-in/out as a simple two-channel (each way) I/O interface, but that runs into more problems with drivers getting in your way (buffering things and whatnot) than parallel ports do.