Imagine that you are a scientist in a highly advanced civilization. Your specialty is xenosociology, studying alien societies. You’ve been assigned to an industrial civilization to study their transportation system. Maybe your trying to prove some obscure theory, you’re a sociologist, after all. So, you turn on the cloaking device and hover over one of their large transportation hubs. You want to watch a place where train, cars, buses, and airplanes all intersect. As you’re hovering over flight UA446 at O’Hare Airport, you realize that people are starting to gather under you and point up at you… you have an OH $#!# moment when you realize that the damn cloaking device has crapped out again. You step on it and high tail it out of there as fast as you can.
So, say there IS some xenosociologist out there who flubbed his assignment and let the subjects see him? He probably wrote a best seller back home and got on Gorlock-Oprah. The stars in our galaxy vary wildly in age. There are solar systems out there that are millions or billions of years older than ours. I’d say we’re pretty early on the civilization curve with only 10,000 years worth of history. It’s not hard to suppose that a cloaking device would be standard issue on an intra galactic spaceship. Human nature being what it is, and that nature being the same everywhere, I can see someone doing a shoddy job fixing the cloaking device, and causing an embarrassing incident.