Maybe it's the fee. One of the three fee options, "the cost of one cab permit per drive", would put them out of business in New York, Chicago, and San Francisco. It would be survivable in Austin, but it would set a very bad precedent.
Unless I misread http://kut.org/post/explaining-exactly-what-yes-and-no-vote-... a 'yes' vote would've meant the fee must be 1% of annual revenue, whereas the 'no' vote means they can still pay that amount, or have two alternative options if they prefer.
So at that point I'm not sure why that would upset them, except perhaps the fear that the 1% option would then be separately phased out later? (which is possibly a very real risk; I'm seeking synthesis, not antithesis, here)
