Yes, Bruce Lee popularized Kung Fu.
When we talk about Kung Fu, we think about Bruce Lee, not James Lee or others though they may have contributed their parts but not as significant as Bruce Lee.
Bruce Lee = Kung Fu.
Bruce Lee started the Kung Fu craze in Asia first with his Big Boss and FOF both made in 1971 before the Kung Fu series. Then follows by ETD, the worldwide Kung Fu craze. The influence of Kung Fu series as compared to ETD is really minor (only in the U.S. and some parts of the world). Bruce Lee and his Kung Fu movies help popularize Kung Fu. No doubt about that.