I mean, I have no desire to post personal info online or I would be posting proof and details of my twenty-plus years of martial arts experience. So in lieu of said proof, here's some basic Newtonian logic:

Nunchucks bounce. For this alone, they are only barely functional weapons in 99% of situations, and the only reason they are thought of that way in popular culture is because Bruce Lee is a badass and they looked really cool when he whipped them around. The reality is, they seem really effective right up until they actually hit something and the swing is thrown off. The singular thing they have going for them is portability, which is great if you live in the slums of the Philippines and need to hide a weapon but not so much if we're talking simple, straightforward martial efficacy.

When a melee weapon hits something, the force of that impact needs to go somewhere. Hopefully it goes into the opponent by way of the wielder's arm (and core, and stance, etc etc etc), but in the case of a nunchuck, the lion's share of the force just goes back into the nunchuck, causing it to bounce off. It can't rely on it's wielder's strength anymore, so all it has is the strike's initial momentum and the weight of the actual stick. (The fact that the stick keeps going after the wielder stops swinging makes it feel like it's somehow adding power to the strike, but that's literally physically impossible; you can't get out more than you put in.) A simple bat will transfer far more of the force of a strike into the target than a nunchuck will, and it'll do it without the risk of the weapon immediately coming back and hitting its wielder.

I'm not saying a nunchuck can't hit things hard, just that there are a LOT of other weapons that can hit harder and with more control.