Are you underestimating a British government's willingness to sell off 20- or 30-year-old Malta-class carriers?
Short answerHe thinks their operational visibility during late-Cold-War and post-Cold-War interventions would have made retention and replacement politically attractive.
NotesCarriers entering replacement age in the late 1980s or 1990s would have been highly visible tools during an activist period of British foreign policy. Their recurring use for air support and international presence could have strengthened the case for retaining them and funding successors.