The empirical evidence doesn't support such an assertion and the burden of proof should be on them to prove it does what they claim, before infringing on everyone else's property rights.

Check out Against Intellectual Monopoly for that argument. Stephen's Against Intellectual Property also covers the empirical case, but adds more to the philosophical case, which he was more interested in.

If it's a topic that interests you, you can find any of the hundreds of interviews, debates, and pods that Stephen's done on the topic, pretty easily.

I'd also suggest you think about whether the disincentivization case even makes sense from an auction theory standpoint. I've never worked it through myself, but just casually thinking about it, it's not clear that the current system of all-pay auctions is better in terms of expected payoffs. All-pay auctions reduce the amount contestants are willing to invest in the first place and yet still manage to often generate social losses. We might actually be getting much less far in intellectual production than we otherwise would and at greater cost.