The Linux kernel or other critical pieces of software infrastructure cost billions to create - yet it is available for free allowing companies to create immense value to society on top of it.
The amount of cool stuff people have created on top of Stable Diffusion since it was created is also amazing and would never have happened if they didn't release the weights.
Like blender Integration to generate assets for your (graphic) models and and full blown video sequences generated from a single prompt.
The resulting storm of new applications was definitely interesting to watch, though none of em were really market viable with that version of the model.
The amount of cool stuff people have created on top of Stable Diffusion since it was created is also amazing and would never have happened if they didn't release the weights.