The main issue with audio jack cables is that they are not designed to carry much power (Jacdac cables are rated at 1A). You get different voltage drop dependin

The main issue with audio jack cables is that they are not designed to carry much power (Jacdac cables are rated at 1A). You get different voltage drop depending on what cable user bought at the gas station. This is a problem is you want to run a small servo or even a few neopixels on a module. Another issue is that the connector often short while plugging-in and out which may cut the power to your entire bus, resetting everything. Not a great end-user experience. There is also a risk users will plug Jacdac to their headphones, possibly burning them.