In my opinion, it's Single Target by far- to the point where I think having an all-attack normal is a definite nerf to the job.
For one, taking care of the most important enemy is majorly important in my opinion, and it's much better to take care of one enemy and then move on the rest. If there's a group of enemies, basically every primarily offensive job have a multi-attack move, and apart from Cat, they all get them early on.
If the player is using the job, then without a single hit move they actually can't control who the team aims for, and that can be bad sometimes. There might be a fight with a Fiend but the other enemies have lower HP and the team goes for them, or it might be a boss like the Calc King who summons allies, and there are many times in fights like that where you just want to attack the boss. With a lack of control, it's a real nerf.
The 4 classes with a Multi-Hit Normal are Thief, Pop Star, Flower, and Vampire. With Flower it's perfectly fine- the are not only a healer and don't need to use their normal, but they get Bluster really early on.
Vampire has Bit and later the far superior Bat Tornado to target a single enemy, so Vampire's fine.
Thief is the iconic multi-hit user in my opinion, and I'm not 100% sure about them, how single hits work for them, as I have little experience playing that job.
But the worst is definitely Pop Star- they have no single hit attack and are forced into the problems I already mentioned, which in my opinion is the single biggest problem, the only problem, actually, with using Pop Star as the protagonist. And otherwise, I'd honestly say Pop Star is one of, if not the best Protagonist job.
The only niche to them if the job (usually Thief) is Hypered, which I admit is very good, but still. Besides, all of the Multi Hit jobs have pretty bad damage output anyway for their normals. Thief's is just acceptable but the others are bad.