Churchill [...] inspired millions of individuals to act
  directly against their self-interest

If a Brit is equally happy living under the Nazis or a British government; or if military victory is impossible for the Brits; yes.

But if most Brits would prefer to live under British rather than Nazi rule, you have something game theorists call a "Cooperative game" and it may well be more profitable on average for /everyone/ to fight rather than for /no-one/ to fight. It can even be in the self-interest of a /coalition/ to fight, tolerating non-fighting free riders, as long as the coalition remains large enough to win.

In other words, Churchill convinced millions of people to act in their /collective/ best interests, rather than their /individual/ best interests.