Is the incentive even necessary? It would be worth testing if there are enough scientists who are keen to promote information sharing in their field without some minimal reward
I also wonder if this will make the penalties for uploaders more severe since it becomes a commercial act
But this is one of the better applications I've seen. Running centralized infra for this specific case is extremely difficult and, generally speaking, it makes sense to give people the option to express to willingness to pay for what's essentially a priority request.
This isn't pay-for-access, it's "I'll offer some reward for you to get the paper now, after which it is still accessible to everyone."
My big quibble is with the implementation: there really doesn't need to be a sci-hub memecoin. Monero is purpose-built for this sort of thing. Use Monero (or zcash, I suppose.) Easy litmus test: if a DNM opened up that only supported transactions in its own "memecoin", how many people would take it seriously? Zero.