I think Chinese (or Japanese) is a good analogy for kata. If I copy an ideogram without understanding it, I may believe I've copied it exactly properly, but might actually make a mistake because I don't understand the drawing. This is especially true of written calligraphy, because there is some interpretation in the strokes. If you don't know the language, it's virtually impossible to figure out what's interpretation and what's error.
I hang around the dojo after my class sometimes. The black belt class (really, just a study group for the BBs) starts right after us. I watch them go through some kata, discussing the nuances. This isn't Isshin-ryu, so I can't say how similar it is, but it's a very structured, kata-rich Okinawan art (Shorin-ryu) that has folks with many years of training still discussing the interpretation of moves.