Faulting a technology for its malicious uses is a common fallacy, but a fallacy nonetheless. Not saying you're wrong (you're not), but it's not a valid argument against JavaScript.
If something is ubiquitous it will be used in its most extreme negative form.
This is why things being generally available that have the potential to be harmful causes such a debate, because on the one hand it’s useful, on the other it’s harmful.
The reason people blame the tool is because the tool enabled people to be able to maximise their harm, and people will maximise harm when given the opportunity.
In this case: JavaScript enables people to externalise their processing cost into people’s own computers, which is a huge potential for harm as it’s a really asymmetric power dynamic.