Pan-STARRS was commissioned primarily to detect earth-threatening objects, a mission first proposed by - wait for it - Arthur C. Clarke in 1972. 'Oumuamua is part of the 1.6 petabytes of data that isn't things that threaten earth. First light on Pan-STARRS was December 2008. 'Oumuamua was discovered in October 2017.

The argument against LIGO was that it was only sensitive enough to observe black holes colliding, an event that the astronomical community liberally predicted happened every hundred years or so. Conservatively, maybe every thousand. The first run observed zero gravity waves in ten years. The second run, with improved interferometry, observed three in nine months.

There is exactly zero coincidence in Pan-STARRS' discovery of 'Oumuamua. It uses the methods used to discover Pluto. None of the other 1.6 petabytes' worth of observation, however, has found anything quite as weird. On the other hand, LIGO discovering exactly what it was designed to discover 50 times over had the effect of demonstrating conclusively that black holes collide a fuckton more often than we thought before we had any data.

The purpose of observation is to generate data. Generating data and going "hmmm.... this data is peculiar" is how breakthroughs happen.