Path dependent accidents of popularity don't mean much.
if Tcl has these advantages, why is PHP more popular?
Because popularity often has very little to do with quality, of
course.
Why, is not entirely clear - as far as I know popularity is
not yet a scientifically understood phenomenon. But the fact
has been well known for a long time, perhaps for millenia... As
Paul Graham pointed out,
there's good reason that the common phrase, degenerates
into a popularity contest has a strongly negative connotation.
Talli's final answer above is right, of course. Btw, I don't often
think about such marketing questions and techniques, so I'm glad to
heard this sort or thing every once in a while from those who have.
