Disagree, it doesn't force anything to be anything else. It is what it is and it's pretty intuitive. PHP never claimed that arrays behave O(C) when accessing members†. It actually reduces complexity because there's only one container type. "Harmful" is ridiculous hyperbole, that's how the language is designed, you may not like how it's designed but not liking something doesn't make it harmful.

† btw, have you seen this? https://stackoverflow.com/questions/2473989/list-of-big-o-fo... pretty detailed investigation of big-O for PHP arrays