Typescript has something resembling nil as inherited from Javascript, so presumably that's what you are referring to. C and Javascript are the most widely used languages in existence. Clearly they weren't kneecapped. It mightn't be to your preference, but "I don't like it" would be an atypical use for the word "kneecap".

There is a stronger case to be made for the other two. Calling GOPATH a design mistake is a stretch as it was perfectly suited to use within Google, but it didn't fit the typical solo developer's environment. Lack of generics made writing certain types of code difficult. You could be convincing in suggesting that Go did end up being used less than it otherwise would have because of those choices.

iota? It's just a construct that generates numbers (an enum). How does that kneecap anything? If it really bothers you, you can manually number the values by hand instead. Why would anyone reject a language because it allows you to optionally choose to have the compiler assign numbers automatically instead of forcing you to do it manually? The answer is nobody. In fact, most popular languages have something equivalent to iota.