Splitting at the joint isn't the only concern. The clamping force of a threaded joint is the entire job of the pin. The clamping force is a function of torque, pin diameter, and friction. The pin diameter is constant, the torque is dependent on the strength of the user (limited), so when the pin is tight, the friction in the pin reduces the clamping force. Basic, and provable. I did testing on this for Airbus.
Beyond that, tight fitting pins do absolutely nothing for the cue. It doesn't assist in alignment or repeatability of assembly. All it does is make it harder to assemble the cue.
I really don't understand why people think tight threads are a sign of quality. I've been around a lot of things that are much more critical than a cue joint, if the threads were as hard to assemble as many cue joints, the part would generally be rejected.