Even at Google, the tendency is (or was when I was there), to only profile things that we know are consuming a lot of resources (or for sure will), or are hurting overall latency.
Also the rule (quote?) says "speed hack", I don't think he is saying ignore runtime complexity totally, just don't go crazy with really complex stuff until you are sure you need it.
That depends on which part of Google. I worked in the hot path of the search queries and there speed was extremely important for everything, they want to do so much there every single query and latency isn't allowed to go up.