Eh, no. FF III is and will always be one of the better FF games out there, with a deeper plot than its NES-appearance might expect you to believe. A plot that IX, for example, gladly took from. Its villain also had a better motive than the villains of IV, V and VI (who were all evil for the heck of it, or mind-controlled), fancy that!

I'd take III over VI (the worst in the series) or X (the second worst) ANY day.