Economic discussions can involve a similar pattern. Consider the (relatively value-neutral) argument that financial regulation is necessary in order to most effectively prevent financial crises while maintaining a robust financial sector. Trumpeting the virtues of deregulation and the free market in opposition, however virtuous they may be, does nothing to address the actual question: how do we ensure that financial crises don't happen? Objecting to spending on particular projects by referencing wealth redistribution or fiscal profligacy doesn't address the details of the goals of the project, which could range from providing unemployment insurance to paying for veterans' disability care.
To sum up the point of these examples, principle-based arguments constitute a totally different kind of rhetoric than consequentialist ones. This can lead to a real impasse, particularly surrounding sensitive social issues like sexually transmitted diseases and dealing with the objection of certain religious groups to protective measures. In these cases, someone's religion prevents them from compromising. Effects are irrelevant to someone with a biblical mandate.
This does not always fall neatly along political lines, either. For example, activists on the left opposing Israeli settlement expansion are split between those supporting a two-state compromise settlement and those in support of a one-state solution. The pragmatic argument for a two-state settlement is strong, given the nearly global consensus. On the other hand, a particular interpretation of the right of return of Palestinians leads many to support a one-state solution on ideological grounds. One side has nothing to say to the other, besides making an appeal to compromise or an appeal not to compromise one's values.
Ultimately, anybody who endeavors to meaningfully discuss an issue has to have both a sense of their own values as well as a willingness to compromise and be pragmatic. Insisting on judging a policy based only on whether it adheres to a particular set of values, besides providing a convenient excuse for not looking at the likely effects of said policy, is not a basis for useful discussion. There is a real debate to be had over whether examining consequences or adherence to principles provide a better basis for ethics. But politics is fundamentally about how people with differing values compromise and form policies whose effects are acceptable enough to all parties involved. Ignoring this, at best, turns political discussions into a morality play. At worst, it prevents any useful communication across boundaries.