I dont totally disagree with you that single target gains have merit, but in all the voidwatch ive been in, on any job, ive always been in fairly limited party, with either DDs, or mages. Im not expected to give boost spells as whm either, but if the nm is procced, i can run forward for 10 seconds to boost str, and the DDs seem to appreciate it. Ive yet to have a Thf, or a Nin, Or a Rng for that matter in any of those go "No dont give me strength, i want agi/dex!" because most of the time they wont get any of those gains/boosts as is, its just a nice bonus i can provide, and if im in the mage party (once i get it) i can pass around INT, as im less likely to be with other whms. If i were on rdm, it would be even easier, because the whm and the melee would likely be separate most the fight (to avoid things like MPK when hate is pulled) so i dont personally see much chance to actually need a particular single buff.

Also hate to nitpick it but your last statement made me scratch my head. I mean, i know what you are tryin to say, but the way its read is "Casting more buffs gives you more time to do other things than cast those buffs!" which doesnt even make sense to me. How can spending more time casting more buffs give me more time to not be buffing? Like i said, i get what you mean, that with our set bonus we wouldnt need to cast them as often, but still needing to cast them more than one time creates wasted time in my book. Theres few (if any!) situation where me casting just a single buff one time to affect most/all of my party would take more time than casting the same buff 3+ times across the whole party.

I see what you're looking at, but i respectfully dissagree, and being able to cast buffs on more people will always create more "downtime" to perform other tasks. Id rather not have both a cluttered enfeebling, and enhancing schedule at the same time for example, so being able to get my buffs down, and focus enfeebling, heals, nukes, and melee as well as reapply debuffs as needed means less micromanagement on an already busy schedule!

And most of all, it wouldnt really hurt the solo functions i do either. If theres nobody else to get casted on, then the spells are as good as single target anyway!