Jumbo frames aside from the usefulness of bigger payload for mpls/tunnels etc add some value in an environment where there's some packet loss.
I would have thought it makes it worse, assuming a physical fault resulting in a constant bit error rate combined with larger packet size means higher probability that a packet is corrupted (as there are more bits in it). The resulting packet is discarded which is a bigger loss than discarding a smaller one.
For example in an environment with say a 1Gbps link where packet loss is .1% with 1500 byte MTU you get 28Mbps througput. With Jumboframes that leaps to approx 162Mbps.
Can I see the maths behind this? If you're talking about packet loss due to congestion and not using TCP then you're probably right