It pushes people to find hacky solutions when they need "just this memoization for this simple use case" and years later when you take over the project you see

It pushes people to find hacky solutions when they need "just this memoization for this simple use case" and years later when you take over the project you see it's been dumping request data to a publicly accessible folder. Luckily PHP is very damn fast so you don't see it often, but you'll start questioning the whole industry if you are hired as consultant into many middle-to-large-sized projects and see the hacks people have come up with.