It doesn't matter whether Uber actually supported the executive order any more than Lyft did. The idea is out there that they did, well-connected people are loudly talking about how they deleted their Uber accounts and you should too, and going against that marks you out as an evil Trump supporter. Welcome to post-truth politics. Even other claims that're clearly and unambiguously untrue has been winning out over the truth if it fits the narrative better. (For example, as someone pointed out on HN the list of countries elsewhere in favour of explanations that are outright contradicted by it like Trump's business interests.)