LOLPUP, but since when is BLU lol?
Even back in the day, being able to do cannonball for a few K while out of range of AoEs with the RNGs and things on hard mobs was very useful. BLUs were a key part in the strategy of killing the first PW, and were always great for climbing Nyzul. Post abyssea they are amazing due to being able to spam new and more powerful spells while never being in danger of having no MP. Yellow procing too can be impossible at times if you do not have one.