They chose mobility over slow big numbers. I was initially disappointed too but the dungeon experience is actually so much better. I like being able to cast flare without fear of the mob I'm targeting dying. Flare did not deal enough damage for how slow it was. I think this is far from the worst reduction of a job's kit this expansion. (looking at you dragoon)

The elimination of timers reduces a lot of stress that excited people. black mage still prefers high uptime to generate and dump as much flare stars as possible and it still doesn't love moving. Since 7.0, content and black mage have been designed to more engage with constant movement. I think black mage with 3 xenoglossy stacks and 2 triple casts had more than enough movement to handle a fight with enough experience. Shortening cast times and lowering potencies for me is a worse dent to my dopamine than losing timers. At least with timers gone I can hold my flare star gauge and not be forced into ice when a boss goes away or a trash pull dies.

The elimination of timers I think was a good change to allow flexibility without changing how the job feels when played correctly. I believe the shortening of cast time and nerfs to damage were the mistake of this patch. I know i love fast flare in dungeons but i would have kept slow flare If it hit like pre-nerf maduin with no fall off damage. What frustrates me is black mage was one of the hardest hitting jobs in the game since Stormblood and i think the fantasy of charging a nuke is being lost. The singe target damage isn't so bad but the aoe damage numbers are underwhelming. I feel like shooting explosions into aoes should feel more EXPLOSIVE!

tldr: I'd prefer black mage be slow and displaying large numbers on my screen. the timers to me were inconsequential with how much easier black mage procs felt to manage this expansion.