I love when people are shocked because someone decides which tech to use based on the merits of the tech instead of what the current year tech fashion dictates. It's hilarious.
Or, you know, simple things like being able to easily attract people. No matter how I prefer Purescript/Haskell/Ocaml/F#/k or even Idris (not practical but I like writing things in it); if I need people fast, PHP/C#/TypeScript are just a better bet (I am surprised how easy it is to find good people with these skills now; seems unemployment hit these as well?).
For many years we went for the tech that made us implement software faster than others. We picked productive languages (clojure/lisp) or languages to express more with less and with less bugs, we wrote frameworks, DSLs and even a few language etc; it worked indeed and we were faster. However, longer term (5+ years) it would be impossible to find people to update/support the code. The win at the start (sometimes a win that would have us win large fortune 1000 projects over the competition) would suffer in the long term from no-one (outside myself and maybe 1 other person) understanding how it works (other people left/went on to other things etc).
So now we just mostly deliver things in old, boring but very standard tech. Using almost written by us and definitely no custom low level stuff like we used to. Because we did all that work before, we know how to optimise for performance everywhere, how to optimise dbs, how to optimise frameworks and webservers. We do everything according to the standards and best practices; now we know that we can get people in 20 years to work on our code. But it is much much slower at the start; so much setup and plumbing. Very boring and tedious. I guess that's the point.
It's a fantastic reason. Writing code is a job. A well-run business is dictated by factors that will usually dominate language design.
If these other languages were better in a holistic sense, businesses would switch.
I would argue against the "technically superior" position on three merits:
1. Finance,
2. Median productivity
3. Long-term product stability
Network effects mean that familiar languages will dominate. PHP, C#, and Javascript are familiar.
PHP has had staying power because it is extremely well-documented (with examples) for the novice, prioritizes backwards compatibility, and is reasonably if not very productive for most developers. The documentation section of PHP.net is probably the most important language "feature" of PHP - it trumps almost any language design feature you think is important.
It reads easily. It's easy to implement. It interacts natively with JSON in a completely fluid way. The database handling routines are rock solid and fast. The core language team spends a lot time improving the safety and performance of existing code. There's a good debug story.
It's its own templating language - no need to bolt on a hand-rolled templating mechanism. Just PHP all the way down. It prioritizes language features (reflection) that make writing libraries and frameworks easier. It promotes building reusable tools. Important features are pulled directly into the runtime, based on popularity in the ecosystem. The kitchen sink is included and it's portable.
Basically, it's a language that has been developed by people who actually have to build and maintain projects over a long period of time. A useful language is more than it's design.
So why do I see it going down the hole that Perl and ColdFusion are already occupying?
I see the other side: it's a sinking ship. FB comes to rescue PHP, but internally seems to like anything but PHP for greenfield projects: Java, C++, Erlang (chat msg broker), OCaml/Reason (messenger.com app), even Haskell is used for some spam filtering tool.
In relation to PHP, really? Sure it has come a long way recently, but there's too much still in there that can never be fixed.
I dont think what IHP delivers is some sort of "fashion": they choose to be server-side only, pretty old school. The typing discipline is not very fashionable either: old, time tested, established, but not often leveraged for the development of simple websites/webapps.
But it depends on what you are doing ofcourse.