> because that's the way the underlying C libraries also worked

I feel like this is a weak defence of the internally inconsistent behaviour. As someone who has been programming with PHP for over twenty years now, most of them professionally, I still cannot remember the needle/haystack order in these functions, I thank intellisense for keeping me sane here.

As evident with this pipe operator, or with for example Attributes, PHP does not need to religiously follow the C way of doing things, so why not improve it instead of dismissing it as "it is the way it is because that is the way it was"?

It's not so much a defense as it is an explanation of the historical origins. Even the creator of the language doesn't defend the inconsistencies and admits that they were a mistake. PHP also takes backward compatibility pretty seriously and doesn't rearrange things for consistency's sake alone.