See e.g. Al Gore taking flights to speaking engagements about climate change. From one perspective, this is an effective tool and probably even carbon-negative if it leads to effective change. On another level, why is a guy with so many frequent flier miles telling me to fly less? Why is a rich guy who can eat the cost of a carbon tax telling me my plane tickets will cost more? Etc.
I am reminded of the "no ethical consumption under capitalism" refrain, which is sometimes used by people who don't like capitalism to justify taking the absolute least ethical option available.