One could, perhaps, consider "Don't stumble blindly into improving the technology used for automated weapons" an extreme position in the US, but given that it's the country that brought us the atomic bomb, perhaps it is the correct extreme position to take.
If Google disappeared off the face of the earth, every system, server, and employee, mitigations would be in place by the end of the week - and a year later it would be like nothing ever changed.
Let's not overvalue an adserver, free email, etc. These services are important but never life defining outside of the relatively small number of people they have made RICH.
Thats not remotely analogous as the point is about the effects of the magical disappearance of google on humanity. Your analogy wouldnt be how the disappearance of a PotUS would not cripple the US, as that contradicts your view...which I have difficulty grasping.
The sudden disappearance of Gmail would be significantly more catastrophic to communication online (though it would certainly be sorted out in a short amount of time as people sneaker-netted new communication addresses out and re-established the broken lines of communication).
If one finds oneself in such a circumstance, it's a correct thing to do to speak out about it.