Because it'd cost twice as much
The trick to plugging things in in the dark is to use your sense of proprioception to your advantage; your body knows where it is in relation to itself, so if your left index fingertip is on the socket and your right index fingertip is on the connector, it should all be pretty simple from there -- assuming you don't cheap out on cables, you should be able to identify the top side of the connector by finding the USB logo or other tactile-identifiable device. If your cable isn't made like that, find another cable; all of mine are, and I got them at a charity shop for $2 each. Or, you know, just flip it over and try again.
Or, failing that, get a tritium kit tag, which is a little plastic bead with a tiny phosphor-coated vial of tritium sealed inside, and tie it to the plug end of the cable. In a bright room or in sunlight, you can't see it at all, but in pitch-black conditions the light it puts out should be just enough to show you what you're doing while still quite dim enough not to keep anyone awake, and it should last for at least a decade without needing any attention at all.
(Because some smartass will certainly bring it up -- yes, tritium is a beta emitter; on the other hand, I've had one of these kit tags in my keyring pocket every day for five years and my balls haven't fallen off yet, so putting one on a cable-end which you touch for ten seconds a day and otherwise don't come all that close to probably isn't going to kill you with cancer, especially if you do something dangerous every day like driving or going out in sunlight. Take your own risk, or if it's too scary just do something else instead.)