The difference is that the TV can not be used to harm anyone else, unlike computing equipment that can be (and is) used to attack others.

In your example let's replace the TV with a weapon and I bet you will be still found liable for not taking appropriate precautions to secure your weapon like keeping it in a locked safe.

Similarly, most online crime uses lots of compromised machines as its infrastructure. Making their owners/operators liable would actually add an incentive to not buy/operate insecure devices which in turn would put pressure on manufacturers to make secure products, otherwise customers will be afraid to buy them if it can get them in legal trouble.