I think they miss the point entirely. The environment in the cell is mostly mechanical, but it's also dominated by random forces. If you are unable to guarantee where you are going to "enter the sled" or when the "tail hits the ribozyme" then the nop sled seems to be an equivalent feature.

So.. to me, it's odd they invoke "legitimate code." The comparison I'd consider would be "combative code." For example, the old game "core wars." Thinking in that mindset, I can see several uses for a "nop sled" in "legitimate code."