A world class supercomputer isn't the same category of good as a MacBook Air. Most laptop owners would feel worse off in some aspects of the trade, as they would no longer have a portable computer to travel with.
If a Macbook Air nets you the most personal utility from a portable computer, as opposed to a 2003 Thinkpad, your ownership could be used to support rather than negate the "best or worst" heuristic.
A better example to support your position would be if you owned the 2011 model instead of the 2012 model of the same laptop. You could declare ownership of the newer models always nets you greater utility, but that upgrading every year isn't worth the opportunity cost, and that it would be silly to find "the worst" laptop to downgrade to every-time you decide to forego an upgrade.