With ftn pens, you have the pen and then the nib. Because of all the inner workings, a millions issues can happen with the pen part of the equation, all issues large and small can effect how the nib writes.. it's complex.
With dip pens, you have the holder and the nib. As long as the holder holds the nib securely at a reasonable angle, the nib will write. The ink does not have to pass through the holder or through any 'workings'. Not implying either is good or bad, just that dip pens are direct and uncomplicated in comparison.