Splitting waltzes would just make DNC a viable healer in Abyssea.
And splitting BPs would make SMN a viable debuffer. But SE doesn't want jobs to be viable alternatives. They want jobs to be cumbersome and awkward.
I've personally felt that Waltz IV is very difficult to find any use outside of healing unweakened people. III just has such a better recast rate. But I have no delusions that SE would ever attempt to make new content useful, since all they care about is being able to hype updates with words.
But I do agree. It is just ******** that a job using limited points should require timed restrictions. It is about as clever as making a 60 seconds delay on weapon skills, even though they already were limited by TP. (Though haste has more or less removed that restriction these days)
Sometimes I think SE bases their view of balance from monsters. If a monster only can cast every 40 seconds, then why should a spirit or puppet cast much faster? Except they miss the whole point that a BLM or RDM doesn't have 40 seconds delays, and it would make more sense to balance jobs, than balance monsters and players randomly.