Because else you end like this Lisp of "20 years ago" ended up: used in some niches, largely forgotten in the main.
For languages, number of programmers translates to: higher quality and number of libs, better tested, more work on the efficiency, compiler, more companies built around the ecosystem, more tools, more books, more tutorials, more open source projects in and with it, more bugfixes, new APIs with support for the language, new bindings etc.
It doesn't have to be "perfect for everything", but it has to be good in the kind of things that interest the most people people now. Scientific computing ain't it.
Much better to use a bad language with 100,000 programmers than a good one with 1,000, as people reluctant of JS in the past have found out.
I feel this is kind of what happens with php, it isn't the best language, but for someone new in server-side webdev there is plenty of info around the web to solve most problems
For languages, number of programmers translates to: higher quality and number of libs, better tested, more work on the efficiency, compiler, more companies built around the ecosystem, more tools, more books, more tutorials, more open source projects in and with it, more bugfixes, new APIs with support for the language, new bindings etc.
It doesn't have to be "perfect for everything", but it has to be good in the kind of things that interest the most people people now. Scientific computing ain't it.
Much better to use a bad language with 100,000 programmers than a good one with 1,000, as people reluctant of JS in the past have found out.