First, thanks to whoever moved this to the right forum; sorry I didn't notice the Wishlist before.

On the other hand it makes sense to me. With the blue bar constantly available overhead I can see if I have enough PPs to increase one or more full levels of the skill.

But if you've already, perhaps foolishly, trained in the skill somewhat but not enough, it doesn't line up so as to make sense. For example, in this image, both skills have enough PP available to completely fill in the yellow:



But that fact is only obvious for the one you haven't trained in at all, i.e. the second one. Since the blue bar always starts from the beginning, instead of at wherever the green bar ends, it's not always completely easy to see that you have enough PP.

I noticed this when I was going down the stairs to the sewers... As soon as you step onto the stairs going down, everything above-surface becomes fixed, and then gets smeared over by the sewers graphics whenever the camera moves.