I haven't actually studied ethics in decades, but that definition goes beyond those with which I'm familiar. In the real world, it is often very difficult to ascertain what actually benefits everyone. And the answer one arrives at is likely to be highly subjective. For example, in an election we should all wish to vote for the person advocating policies that will benefit everyone, but there will be great disagreement as to which candidate and policies fit the description.

In the present case, it would involve assuming facts not in evidence. Arguably, all use of the policy may benefit REI in the long run. I heard a report on NPR a few months ago discussing this policy. What is the value of such a report to REI in terms of free publicity? Being known as 'rental equipment incorporated' might well be worth more than the cost of returns. If no one "abuses" the policy, REI doesn't receive that same level of benefit because no one really notices. You can return goods to most vendors, but becoming 'famous' for accepting all returns sets you apart from the competition.