This "fair use" argument is excellent if used specifically in the context of "education, not commercialization". Best one I've seen yet, actually.
The only problem is that perplexity.ai
isn't marketing itself as educational, or as a commentary on the work, or as parody. They tout themselves as a search engine. They also have paid "pro" and "enterprise" plans. Do you think they're specifically contextualizing their training data based on which user is asking the question? I absolutely do not.
"Your honor, we can use whatever data we want because model training is probably fair use, or whatever".
I don't know what's worse, the fact that you think creators don't have the right to dictate how their works are used, or that you apparently have no idea what fair use is.
This might help; https://copyright.gov/fair-use/