It sounds from the article like Uber had a $15 minimum already. Now they're dropping it to $12, in "apparent defiance".
Looks like 'earned media' to me, free mentions in the press for throwing a fit.
The thing is that the $15 minimum would have applied to all of the services that Uber offers, not just their town cars. This would have an impact on the rollout of UberX to the area, which has a minimum fare of $10.
Exactly. This was an attack on the new "Uber X" service which will more directly compete with regular cabs. (Frankly the only reason I even take cabs anymore is the cost of the regular Uber service.)
Uber currently has a $15 minimum total fee in DC. They charge a $7 fare (the "flag drop" rate) and then $3.25 a mile after that. The proposed amendment, if I've read these articles correctly, would have raised the "flag drop" rate to $15 and then any mileage charges would have been on top of that. For comparison, the flag drop rate for taxis is currently (and would have remained) $3.
Given that this amendment would have severely hurt Uber, I'm definitely inclined to believe them over Cheh on this.