There are secure key-storage devices like Trezor or Bitsafe. Why there are no full client HW wallets?
Because you can use cheap Android smartphones for that. I have bought one for less then a price of Trezor. I'm using it as BTC wallet only.
Dedicated HW wallet can break as well. All you need to do is backup the wallet, or save the seed.
Malware is not an issue if you are using it as single purpose device. Do not install anything besides the wallet app. Do not even register your google account.

edit: There was one project started by Matthew, to create independent hardware wallet in form of a "smartwatch". Now it's dead.