I don't think Black Mages suck. They're certainly a cool class. However, they aren't meant for my gaming style, so that's why I don't use them that much. I don't want to waste spells except in really hard fights and bosses, and Black Mage still has relatively little MP so I often hesitate to use his spells. FF1 Origins Easy mode is an exception. There Black Mage is probably the best class ever because he has like 20+ MP for Fire2/Ice2/Lightning2 by the time you reach Marsh Cave. But otherwise, I like saving magic a lot. When I get spell-casting items, such as Zeus Gauntlet, Mage Staff and White/Black Shirt, I always use them with my Black Mage instead of having him spend MP on a spell.