Right, but this event just confirms gravitational radiation exists (which we already know). It can't tell us how it behaves (is it quantum? it it classical?) wi

Right, but this event just confirms gravitational radiation exists (which we already know). It can't tell us how it behaves (is it quantum? it it classical?) without detecting many events in sequence to be able to run statistics on (and if you miss one, your stats are wrong). One bar has a very low probability of detection, we'd need many, hence the expectation of planet-scale machinery.