Why was this short, not thought-out, question that had no evidence of any attempt get so many up votes? Were things just that different 2 years ago?
Same with the UX question Do we need good-looking design for a program internal only to our company? which I posted on Reddit on April 16 (notice the spike in its timeline).
Obviously I can't be certain that all their traffic came from my Reddit posts, but I did get gold Publicist badges for both questions so at least 1000 unique visits on each are my fault ;P
But there aren't really any vote spikes in the integer division question, the most votes it got in a month were 9 in Nov 10, when it was first posted. Although I don't consider it a good question by any standard, it's age and noobesque quality probably account for its votes. Questions like this are a good reminder that votes are not always a sign of quality, as they can be so easily manipulated.
I think it is the phenomenon of herd and badges.
I see it a lot on Stack Overflow, when question, answer or comment gets high scoring or high view suddenly in a few seconds a lot of people also upvote/downvote/view this.
It's too weird that in a short period of time everybody thinks alike.
Another reason on voting up question is because of people who want to achieve badges like Civic Duty, Electorate, Sportsmanship, Suffrage and Vox Populi.