I would hope that uber has bigger fish to fry by subverting the taxi industry, but strategically I can see why they are as scared of Lyft as they seem to be. Still seems distasteful to sabotage a fellow startup.
I don't see why Lyft being "a fellow startup" should affect any of Uber's business tactics.
Startups don't have any intrinsic motivation to play nice with each other.
At this point Uber essentially is the #1 established company of car services, so them resorting to dirty tactics to fight Lyft leaves a very sour taste in the mouth.