My theory is that their code is shit. It shouldn't be surprising given that their Chief Architect wrote a Medium post (Oct 2016) in which he cited concurrency a

My theory is that their code is shit. It shouldn't be surprising given that their Chief Architect wrote a Medium post (Oct 2016) in which he cited concurrency as one of the primary benefits of PHP, and advocated for "curl'ing to localhost" to achieve parallelism.