FFXI spells were too short and rather lackluster compared to their offline counterparts. I always attributed this to hardware limitations, so it wasn't a big deal. In FFXIV the spells are toned down even more than FFXI. Perhaps Tanaka wanted to go with a more 'realistic' look with this game, but I don't think it was a good idea.

I suspect that a large-scale revamp of the magic effects is planned but won't happen until after the class system is addressed. So as others have said, this is just a small tweak to bridge the gap.