I don't know the situation, could be way off base, but just as devils advocate type take: NIL isn't salary. It's marketing.
Have you all seen that LSU gymnast (I think?) that is making a boatload in NIL? It's all because she's a social media influencer, and good looking. Couple million followers on instagram I think? Nobody tuning into gymnastics of any kind to justify that type of money as a salary. So, say all that to say if this walk on has a huge following on YouTube or whatever, for whatever reason, then there is value there in an NIL type deal.
I'm with you all on the general sentiment of college football and the direction it's taking though and NIL is a big reason.