This is not to be blamed on WhatsApp whatsoever, but on the carelessness of the victims or intending victims. And this has nothing to do with the end-to-end encryption, they are different things.

WhatsApp is not an antivirus, so it's not responsible for the security of your gadget. That's why you should be aware of the havoc that what you download or the link you click on can cause. This is not the first time people have been downloading malicious programs through online communication, so WhatsApp shouldn't be blamed for any reason. We are responsible for the safekeeping and protection of our gadgets.