As the sibling comment says, user actions are the main driver, but also the fact that the weights can be modified. If a model is released with safeguards, they can be ablated out or the model can be fine tuned for nefarious purposes, and nobody can really stop that from happening.

That’s not to say that the majority of open weight models are being used in nefarious ways or are dangerous, but unfortunately despite (hopefully) most people being responsible, we have to guard against the small number of bad actors. Like with everything, a small number of people ruin it for everyone.