The fuse's main purpose is to protect the board; the diode is easy to replace and in the same cent price range anyway. Once the tripping current is exceeded and it blows, the electrical circuit is interrupted and there's no more current to do any harm.
Alternatively, you could put a resistor in series with the diode, limiting the current to a non-destructive level. However, the termpower design is poor enough as it is (delivering only 4.3V, Vterm should be more in the range of 5.25V), so that would require a bit of redesign... Ever done that, mechy?
