There are many that feel that way but also many like myself who much prefer a cartridge/converter system over most any other type of filling system. In fact, my preferred filling system is by cartridge.
With my Aurora Africa's piston turning knob, simply fallen off when I recently went to fill the pen, I have joined the converter/cartridge preferred club.
I actually consider the filling mechanism each time I receive a new ink & leave any cleaned piston filled pens in their empty state, while selecting a "CC" filling pen to fill. Until I decide about the ink & it's properties, there is no reason to repeatedly flush a piston filling pen to clean an unknown ink until I am sure I want to continue it's use. The filling system is merely one aspect of a pen's attributes & is of very little importance to me.
S T Dupont's seem to have sold pretty well with their simplified filling systems & I would imagine their lack of piston filled pens has not kept many users from purchase.