That's an unfair way to look at this. Should it be as good as a fighter? No. But it still has to be objectively good and it just plain isn't when stacked up to other class options.You are setting yourself up for disappointment if you compare a caster who dabbles with melee with a full melee class.
This is a problem with a lot of the sub-classes. There are very clear good and bad choices which in turn don't really make them choices other than to choose to have something that isn't as good as another thing. I think the best thing WotC could do isn't to introduce new classes and new sub-classes, but to go back and rebalance everything in a revision. At this point I wouldn't even care if they called it 5.5e, but I do think that it needs be done. When the core of a system is imbalanced, it cascades to everything else produced that is based on it.