Writing AdSense or GMail in Ruby/Python/PHP will force you to pay the "tax" later on and the tax will be huge before you know it. You'll end up with a scratch re-write like it or not.
I'm not sure what you're trying to say here. Is the "tax" the upfront cost of writing code that uses static typing? If so, I most strongly disagree.
Static typing is not a silver bullet. The claim that not using a static typed language for anything complex will result in a "scratch rewrite" is absurd.
Static typing is not a silver bullet. The claim that not using a static typed language for anything complex will result in a "scratch rewrite" is absurd.