I think the terminology is an attempt to link the software version to its hardware predecessor. Passive filters have hard limitations dictated by their component values, so you have no choice but to substitute different components if you want to extend their capabilities. That's why they had three separate hardware modules.
Of course, no such limitations apply to software emulations, but part of the sales pitch is that the plugin emulates a piece of hardware. You could, I think, think of the term "module" as a coarse preset and "preset" as a set of fine adjustments within it. Just my interpretation.
At the end of the day, it's a simplified parametric equalizer that hides every parameter except gain, making a large number of presets necessary.