Also agreed, I'm quite binary, if not caricatural, in my characterization. But it gets the point across, and I trust readers to put grains of salt wherever appropriate.
This being said, if like most projects, yours is more about reusing existing stuff than about writing software components that have never been released by anyone else before, and better-fitting components exist in PHP than in Python, You'll be better off writing ugly and not-fun PHP code. Some people can swallow this, others can't; the latters are probably better off not going the startup way.
You can always argue "Oh! you are doing "that" use <said language> it's amazing and has that built in." However we find that Python focuses a lot on the programmer as well (white space etc...) and that was the tipping point.