Unjust or not, the issue then becomes one of whether or not it acceptable to try and change a law by wilfully violating it - as Uber et al are doing in some of the locales they are operating in - with the implication of whether that slipperly slope is *really* one that you want to go down, and especially so when it's a corporation making that decision just because it's inconvenient to their business model/profit margin. In some cases, sure, mass civil disobedience is necessary to bring about change, in others a lone individual might do as a trigger (Rosa Parks, for instance), but generally those are for far more egregious or morally corrupt laws than the kind of bureaucratic red tape and entrenched industry regulation that Uber is opposing.
Yes, much of that legislation is unjust, anti-competetive and so on, just as Uber is claiming, and some of it is also there in order to at least try and establish a minimum standard of safety and service. The correct process for Uber and the like to take is to challenge the unjust, anti-competetive laws first, potentially citing public demand for their services, *then* start operations if (and only if) they can successfully establish a framework that enables them to operate legally and in compliance with the safety and service legislation. Starting operations regardless and dealing with the legal fallout might be acceptable to them, possibly even considered as an acceptable risk within their business model, but it also smacks of "we're above the law" arrogance, which will lose them some of the public support they might have had if they were purely fighting it through the courts and better discriminating between the two sets of rules. Factor in the stories of how Uber treats its drivers when things go wrong, drivers having their cars taken of the road, and even the issue of their status as contractor or employee, and it's easy to see how people who might otherwise be supportive of Uber are not.