This is horrible!

Last night I spent over 1000gil on three pieces of strength materia to add to a HQ Lance (Iron Guisarme) I made for a friend. So I melded two of the strength materia into the two slots then noticed on the item description window that each materia said strength +0!!!

NOOOOOOO!!!!!!!

That's two materia wasted and I'll have to try to HQ another spear to add something else to :'(

Why can't the game stop you from adding strength materia if the strength stat is capped for that item? WHY!?

Why is there no indication or warning that certain stats are capped on an item and can't be improved? Why, why, why? How can I tell if a stat is capped before adding the materia (and possibly wasting it and the item)? D':