The problem is that they never really staked out a good position in the marketplace, especially the last few years. Even bigger stores, think Circuit City which closed a few years back and Best Buy, which always seem to be teetering on the brink, have had a hard time in this space. But Radio Shack had a fairly small inventory and they certainly didn't always have the best prices on things. And, as their situation got worse, their inventory got even worse.
To make matters worse, some stores had very good staff that really knew their stuff and other stores, well, they weren't that good. So, they just didn't have any point of differentiation. And yet, they did have something unique within the electronics chain business. They were the place to go when you needed some components, they were doing DIY before it was fashionable. And maybe, had they double downed on that role, they'd still be doing well.
For example, maybe they could've partnered with Maker Shed and created a real maker space. They had lots of great locations and they could've sold 3D printers, arduino kits drones and the like. They could've led the DIY revolution. They could've had employees as passionate about Radio Shack as Apple employees are about Apple stores. They might've had a passionate audience, coming to them to help with their DIY projects. Maybe a store where people would've gathered to share ideas, a place where there were hackathons on the weekends and people learned about arduino, Rasberry pie and robotics. It could've been the third place for the DIY community. And since they would've been way ahead of this trend, they could've owned that position.
True, they wouldn't have been mass market, so the investor community might not have liked the idea. But they'd be a smaller, better version of what they are today and they might still be successful. And they might not have filed for bankruptcy today.