(an old joke in new context)
Erdogan continues his administration's quest to seek energy independence for Turkey by harnessing the awesome power of Kemal Ataturk spinning in the Anitkabir.
Somewhat saddening on a broad level to see Turkey taking another symbolic step away from the secularism that allowed it to develop faster than some of its neighbors. But, at the same time, the country and its people are not beholden to an amorphous outside desire to maintain the status quo and have different ideas of what is in their national interest and character going forward. Hopefully they do maintain the site's openness--but this erects a barrier that could be made higher and more restricting in the future should Erdogan or a successor ever wish it.
The quietness it will be addressed with by many in the UN in comparison to the uproar that would ensue were Israel ever to act similarly is something else, though.
This is EU's own fault. In the name of Europe's dogmatic take on how "liberal democracy" is supposed to be like, the Turks were made to neuter the military and it's ability to step in and tell democratically elected government that no, they don't get to do this and that (if doing so undermined Turkish secularism).
Eurocrats did not bother taking Turkish circumstances into account, and EU's democracy fetishism naively assumed the Turks would always vote secular / liberal / progressive, ignoring the possibility of Islamists voted into power completely, almost per definition.
Also, EU was acting deliberately in bad faith, Turkey was
never* going to be permitted to join the EU no matter what concessions they gave. EU bureaucratic establishment thought they could keep the Turks waiting indefinitely in the antechamber without any ill consequence.
*As doing so would have changed the internal power dynamic, adding Ankara to Berlin-Paris axis (with a side of London back then) running the show.
So it should come as no surprise the Turks with their proud Ottoman tradition / legacy gave the Eurocrats one big "f*ck you" voting as they did.