I said this in another thread, but I wonder if Kalanick saw the writing on the wall that Trump and his administration could not be reasoned with, and these protests against the immigration EO (and Uber's snafu) gave him an "out" based on external pressure.

I'm reminded of Eliot Cohen's response after trying to work with the administration in good faith:

After exchange w Trump transition team, changed my recommendation: stay away. They're angry, arrogant, screaming "you LOST!" Will be ugly. https://twitter.com/EliotACohen/status/798512852931788800