Security is certainly important, but do not forget that for many people a cold wallet will have a number of drawbacks. For example, like losing a key or transmitting it to other users, viruses, etc.
Don't lose your keys or seed! Store them in multiple locations. Write them down properly and check if you can read every word/letter. Archive and encrypt them on multiple offline locations. The whole point of all this is to be the one and only who controls this data.
You can use hardware wallets even on unknown or infected devices because the private keys are stored in a secure element.
When ForkDelta was attacked via a DNS service attack last year those who logged in with their private keys lost their funds. Those who used a hardware wallet to log in didn't.