An argument I've heard advanced for both PHP and JS is that their evil is well-documented and well-understood (e.g. one of the Facebook efforts was to write an extensive spec for PHP). Contrast this with, say, Python, which is much more nicely designed, but implementation-defined and with some gotcha areas with poorly understood and documented behavior - rarely encountered, but when encountered, hard to grok or avoid, also because they can readily keep changing from version to version (some of the corner case details of slots come to mind as an example).

I can see a pragmatic point there - anything has warts, the warts you know and don't move are easier to contend with (and lint for). I'd still pick Python for most projects in that comparison, but at a certain scale of effort I'd possibly begin to wonder about the trade-offs.