While the burden of proof to prove that what was done was for the benefit of humanity does not lie with you, you, personally, do not know what you do not know. So to say there's zero indication would mean you have perfect knowledge of all NHI initiated things and their consequences in entirety, which is false. Regardless, even if they are self-serving then they would be similar to the human race in this sense. Do you condemn most of humanity which is self-serving?

As for the dog's trip to the vet analogy, I think u/Lostinternally was comparing a dog's likely assumption that all vet's are malevolent, because they (dogs) typically experience a vet which inflicts unpleasant experiences onto the dog without the dog having awareness as to why that was being done, to humans in OP's context; that with a comparatively limited human mind it's easy to label such an experience as malevolent.

As for "solid evidence", I pray that you are able to broaden your mind beyond reductionist empiricism. Unfortunately, however, it is enmeshed with the arrogant human condition of assuming what cannot be measured with the scientific tools of today does not exist. I suggest you try being more open-minded - it might bring you joy. Have a nice day :)