Even if the manufacturer is out of business, you can still access your coins. The algorithm for creating the private key is public (BIP39, BIP32, BIP44), as is

Even if the manufacturer is out of business, you can still access your coins. The algorithm for creating the private key is public (BIP39, BIP32, BIP44), as is the actual firmware source code. The recovery is through a web-based tool, but the order of the words is randomized and displayed only on the device, so even if someone installs a keylogger on your PC, he would need to know the correct order (since it's 24 words, that's safe enough). (Disclaimer: I work for SatoshiLabs, the manufacturer.)