No matter how you slice it, even if the times of the WQ rotate every month as a mod in-game suggested, there's always going to end up being people who miss out. Be it sleep, school, work or illness having a single set start and end time will end up unfair to at least a few time zones.
The pool of available IV points is also significantly too low to allow a decent number of people to participate in the event, our WQ started in the middle of the night my time was over in 7 hours. the next one starts right when most people would be going to bed for work or school in the morning. At least half the player base didn't even have a chance to participate. It's also frustrating that the best place to hunt Gold's WQ Pokémon was locked behind a quest, once again giving an unfair advantage to certain players.
Suggested fixes:
Allow players to manually start the WQ at a time of their choosing within a 24 hour time period, give them a certain number of hours to reach a smaller IV pool.
Expand the IV pool so it's more likely for the WQ to last the full 24 hours, thus giving everyone around the world a chance to participate.
Host four separate WQ events through the day, every six hours. Do not allow people who have already participated in the WQ for the day to participate in a second one, again allowing everyone a chance to participate.
Also do not pick Pokémon whose best farming location or only repellable location is located behind a quest wall. If this is supposed to be a special event that only occurs 12 days of the year then everyone should have a chance to participate in it and be on equal footing.
I personally think that the third option is the best solution to the issue while still keeping the spirit of the old system in-tact.