None of the language you mention had any sort of wide-spread visibility at that time, meaning they were not representative of the (overwhelming) majority experience with statically typed languages.
As far as I'm aware, Pascal and Ada were still significant in the early 90s (ie when Python arrived). You're right that they where far less so when PHP entered the picture, but it's not as if they were dead (Borland Delphi and PHP 1.0 were realeased the same year).
> Pascal and Ada were still significant in the early 90s (ie when Python arrived).
That is not the timeline we're talking about here. Dynamically typed languages started taking off at the turn of the millenium and really exploded in the second half of the aughts. Java didn't even exist in the early 90s.
But it's not as if the programming community collectively just forgot about these languages (and, as mentioned, Delphi and PHP are in fact contemporaries). The question remains, why did new dynamic languages rise, but already existing static languages decline? That requires an explanation.
None of which really had mainstream visibility with the kind of people who actually made the decisions about what language your company would be using.
And Pascal, Ada, Haskell, Eiffel, Standard ML, ...