Its important to consider others perspectives, even if inaccurate. As it was expressed to me when I suggested "why not write a blog" to a relative who is into niche bug photos and collecting they didn't want to give their writing and especially photos to be trained on. They have valid points honestly and an accurate framing of what will happen, it will get injested eventually likely. I think they overestimate a tad their works importance overall but still they seemed to have a pretty accurate guage of likely outcomes. Let me flip the question, why should they not be able to choose "not for training uses" even if they put it up publically?