So?
Japan is quite knowledgeable concerning stealth. The type 12, ASM-3 and so on goes through rigorous testing before going on as well as the enhanced type 12.
Japan is also the forerunner in material science, the key component to stealth.
Do you really think the engineers are just going to patch something up because they think it looks cool?
They are. Thus why the Type-12 looks the way it is, it is profitable.
But you seem to only value the low altitude flight. Which i havent address.