Why? Point a gun at big obvious target doesn't take intelligence and only minimum skill.
They don't need to have any knowledge, just shoot the big squarey boxes till the lights go down. Or hell [1] ask the internet what will happen
> There's all this incredulity in this thread but really, some dudes are gonna go knock out an entire power substation to rob a cash register? If I were one for Occam's Razer...
Actually, random terrorist act would probably be great way to keep local police busy for some time if you wanted a distraction for something else criminal to happen...
"Crazy rednecks doing stupid shit" is more simplistic explanation, but not that much more.
* [1] https://www.quora.com/What-happens-when-a-person-with-an-ass...