Because people wants to do it easier. Why doing it the hard way if you can make profit easily?
Yup, that's what players want, easy profit or else they hardly do it. It is also one reason on why some of the good players who can beat Ifrit flawlessly aren't fighting him again, because either they have all the weapons or they don't care about the fight anymore. Then after some months you ask them for their help and make the party lose because they aren't used to it anymore =)