The alignments are exactly on the same scale of the filaments. It would be a contradition to the cosmological principle if, say, the alignments occurred only on one celestial hemisphere.
Is a line of basketballs all found to be spinning in the exact same direction more or less random than a line of basketballs spinning in random directions?
“A correlation between the orientation of quasars and the structure they belong to is an important prediction of numerical models of evolution of our Universe. Our data provide the first observational confirmation of this effect, on scales much larger that[sic] what had been observed to date for normal galaxies,” adds Dominique Sluse of the Argelander-Institut für Astronomie in Bonn, Germany and University of Liège.
I know, I know. "Sufficiently large scale."
(lol)