The Circus Died Because The Circus Sucks
Pretty much everything has a "freshness date" attached to it and the circus is no exception.
Let's look at what makes up a circus. There are clowns, jugglers, wild animals, trapeze artists dancers and people performing "feats of daring". Now let's look at that list again.
People hate clowns. Juggling is interesting for about 30 seconds. People are concerned about those wild animals being mistreated. We get to see trapeze type stuff and dancers everytime a pop artist is on t.v. (and they're in the background, so even they have taken some of the "thrill" out of it). This leaves only "feats of daring" and that usually means people swinging by their hair or some other stuff that looks so incredibly mild compared to what we can see on the internet. There is just nothing exciting about what made up "today's circus".
The circus wants to blame animal rights people for their drops in attendance, but I blame a lack of innovation and the shortening of attention spans for their demise. The circus has left town because it was time for the circus to go.