Crypto currencies will have a difficult future if they are used primarily to make everyone cheat, rip off and shit.
The fault is definitely on Electrum side, there is no doubt in that - hackers use exploit which should have been foreseen and fixed in the way it was made in the version 3.3.3. But it is also the fault of the users, who do not realize that everything has to be checked several times before actually doing something, and update of desktop wallet is highly risky operation.
If you just visited Electrum official site and read warning :
Warning: (1) Electrum is a Bitcoin-only wallet. Variants of Electrum for other cryptocurrencies are not developed by us, and they are not endorsed by us. Some of these variants have been found to be Bitcoin-stealing malware. (2) Old versions of Electrum are vulnerable to a phishing attack, where malicious servers ask users to download a fake version of Electrum. DO NOT download Electrum from any other site than electrum.org.
https://electrum.org/#home