Apparently, you've not played much Metroid, because if you've played it as much as I have, you'd realize that as awesome as Samus' morph ball abilities are, you're still much more effective and harder to hit when you're standing up. The only reason you stay morph balled for long periods of time is to crawl along the ceiling with spider ball, because most enemies can't see you or can't hit you there; obviously Raziel is going to be aware that Samus is up there, and remember that Samus' speed decreases while using spider ball.