I am not surprised. A judge overturning an election is going to be rare, although it does happen.
As a non-Arizonan, I have to ask why Maricopa County conducts elections the way it does. As I understand it, instead of voting at a local precinct, a voter can vote at any of several ‘voting centers’. The complication being that the correct ballot for any given voter has to be printed up on the spot. And if the printers fail for any reason, chaos ensues. And at this election the printers apparently did fail for several different reasons.
The short answer is incompetence.
Scott Johnson at Powerline had a friend (Local Arizona Attorney Jack Clifford) watch the proceedings and guest blog about them:
Day 1:
https://www.powerlineblog.com/archives/2022/12/jack-clifford-lake-v-hobbs-day-1.php
Day 2:
https://www.powerlineblog.com/archives/2022/12/jack-clifford-lake-v-hobbs-day-2.php
The short answer is that Hobbs proved Maricopa County is incompetent, but did not prove it incompetent enough to change the results, and did not prove fraud.