Well, it's all about risk assessment. Curl has had RCE security bugs before[1]. That doesn't mean curl is "downright dangerous" it just means that "it's safe because it doesn't pipe to sh" is also not a correct thing to say.
I suppose 'devoply pattern-matched "curl -sS <sth> | <sth else>" to "don't do that". I think that because that's exactly what I did now; it took me a few seconds to realize that - this time - the invocation is mostly harmless.