I did notice it. The question has given a huge spike in the number of visits to csthoery for one day.
I believe the explanation is simple: someone shared a link to the question on a popular site (Hacker News in this case) which caused a huge temporary spike in the number of visitors. It seems that the question is interesting for general CS audience who may not be researchers in TCS. We have had a number of famous questions with relatively huge number of viewers, this one is not that different.
I don't think it is that useful regarding marketing the site to our target community though. However it is a nice example of a question that can be used for outreach to people outside theory.
Note that regular users from other SE sites get enough reputation to vote on the question, so the total number of votes does not necessarily reflect the quality of the question relative to other questions according to regular cstheory users. (This is one of the issues that I think MO negotiated with SE when they decided to migrate to SE2.0 to make sure it won't happen on MO after it migrates to SE2.0).
This happens also on other SE sites like Math.SE, e.g. the batman equation question. It will happen from time to time, I don't think it is not a big deal as long as it is not causing a problem. If we see that the question starts to cause problem we can make it protected or even lock it (as is common practice on other SE sites).