Such incompetence. They let this horrendous guy off the hook in 2022 (after he was going for hunger strikes saying Ocalan is being treated badly in prison or some shit) so after he wins they take over because they knew they have the guy's sympathies in bright daylight and they can get popular support for the move from the populace, not calculating the local backlash getting out of control which prompted them to give the municipality to one of the most extremes of the terror sympathizers. If this guy was disqualified, the terror sympathizers would have had to opt for someone much less incendiary. But the fact that these guys are normalized and we have to tolerate them is direct result of AKP's and Turkish liberal's stupid attempts at flattering the western actors during the 2000s and early 2010s.
Another aspect is that the opposition has tried winning over Islamists by courting anyone from Ekmeleddin to Davutoglu but they haven't been able to chip away at the Islamist voter base of AKP (which was a lost cause from the get-go as when a conservative religious party owns religion you cannot convince their voters to change their loyalty to those who are, in their minds, not religious and only pretending to be for votes). So after that failed attempt, the opposition has had no other recourse in the arithmetic of voter blocs, but to appeal to Kurds to even have a shot at dethroning AKP due to the demographics. Knowing this and how they have to react to such an incident as Van, the calculus for AKP is an easy one as the MEE article also showed how the AKP insider consultants think they lost this election because the party didn't listen to their clique and their campaign was not divisive enough.