I'm not really engaging in forensics-style debate. If you don't already know why "fast" is so integral to search as a feature that it goes without mention, I don't think we are enough on the same page to discourse on the topic.

I think returning results in a timely manner is more than an acceptable assumption.

The poster clearly thought about search in terms of the existing Google search functionality which is near instantaneous.

Usability matters to the average end user and a delayed search is not usable for most people.