Author here :-) I don't think I disagree with you. JS has its warts and some of them are... weird. The web delivery mechanism has always been its killer feature

Author here :-) I don't think I disagree with you. JS has its warts and some of them are... weird. The web delivery mechanism has always been its killer feature, not the language. And for web delivery mechanism to work, it needs to maintain backwards compatibility. In practice, however, I think a lot of these things become irrelevant because JS subcommunities carve out reasonable subsets of the language. For example when using React you almost never need to care about prototypal (or even normal) inheritance because it's explicitly discouraged by React. And in the future, we might not need to encourage classes when writing components altogether. If you limit yourself to avoiding some features then it's not such a bad language after all.