Why would web programmer think about processors and GHz is beyond me. There are jobs where it might matter, but for most of them it is completely irrelevant.
I know we can treat a lot of the technology we use as a black box, but not knowing even the basics of that technology indicates a lack of curiosity. I'd be shocked to find a competent programmer who couldn't answer the question.
A similar question: approximately how many IPv4 addresses are there?
See also: "Latency Numbers Every Programmer Should Know"
They might have been curious about different things then you. Or more interested in knowledge that helps build stuff ( still constantly learning, but choices are different).
When youre writing a complex SPA app and your performance is dragging on that cheap Android, it's nice to be able to reason about things like clock speed, memory usage, etc.
If they work in high level language that hides all that behind "number", who cares. How floating point numbers are represented is interesting trivia, but hardly useful in most situations. In general, I would expect people to remember things that are used often and be able to learn the rest fast (e.g. understand concepts and have enough knowledge to make further learning easy).
The rest is fluff and hidden cultural test: "Do you have the same history as I do?"
