D/P makes this argument uselessNot necessarily.
Flamethrower is good for special sweepers who do require the accuracy in battle. Fire Blast on the other hand is better on physical sweepers like Blaziken or things like Weezing so they don't get walled by steel types and other physical walls a.k.a. Skarmory. In this case Fire Blast is prefered over Flamethrower because you really need to take out that wall fast, or it will start to wreak havoc on your physical sweeper.