I don't know why, but I have the feeling that protocols that require game theoretic arguments to be proven secure are inferior to protocols that don't. Collateral is always a red flag to me, as it implicitly opens up known and unknown pitfalls down the line. That doesn't mean game theoretic arguments don't have value, but I'd like to keep them as minimal as possible, nicely relegated to a few, very constrained cases. Just my own two cents.