One of the more common legal arguments is that a judge should uphold a law or executive branch decision that the politicians responsible are entitled to enact or take, even if the law or decision is a ill advised as a matter of policy. This is the black letter law in a wide variety of contexts and is generally justified as a way of expressing an institutional preference for preserving the integrity of the democratic decision making process. Deference to jury verdicts that seem to have reached the wrong conclusion from the facts presented at trial is justified in a similiar way. As a lawyer, I get that. I've made these arguments many times myself, and it would be a rare lawyer who wouldn't use them from time to time.
But, when you really look at the structure of this argument, it isn't a terribly emotionally satisfying one, and the more extremely ill advised a law or decision is as a matter of policy, the less impressive the case of judicial restraint to uphold democratic principles and institutional perogative becomes, particularly when the bad legislative drafting, or executive branch decision making at issue seems to reflect an ill considered choice by politicians (or people who report to politicians) or a decision that a sincere decision maker might acknowledge in private was a regrettable one that would have been better resolved in the manner that an activist court is tempted to resolve it.
I don't claim that judges should be judicial activist who substitute their policy preferences for those of elected political actors and their subordinates, particularly in cases where the policy decisions made really were carefully considered and intended by the people making them, and were not, in private, regretted after the fact (even if they are supported in public to save face and protect the authority of the decision making in other situations).
But, I do think that these kinds of doctrines about judicial review overstate the extent to which at the level of detail at which judicial review is applied, the right policy is a matter of opinion, rather than an objective fact within the context of a widely shared and foundation set of values and assumptions built into our social reality and legal and political process. There are a lot of cases where political actors of differing political affiliations will reach the same conclusion about the best policy in a fact rich, specific, as applied situation.
Also, even is judicial actism is wrong, just how wrong is it relative to other problems with our governmental system. To the extent that judicial activism in a particular instance does not have the effect of tangibly undermining the judicial or political process (perhaps, for example, because the publicly given reasons for the decision are insincere, or because the decision is likely to be obscure and little reported), to what extent is judicial activism that imposed a better policy results than a poorly written law or an executive branch exercise of discretion that makes a bad choice, anything more than harmless error?
One can acknowledge that judicial activism is, in the abstract, wrong, while at the same time agreeing that bad laws and bad executive branch decisions regarding how to exercise their authority is also a bad thing. Indeed, if a risk of judicial activism discourages legislators from writing bad laws and discourages executive branch officials from making bad decisions, judicial activism may not only be a harmless error in the individual case, but may be harmless error at an institutional level.
For example, even if there is no credible legal argument for the proposition that it is unconstitutional to prosecute someone for witchcraft exists under a given country's laws which have a statute permitting prosecutors to do so, judicial activism that invalidates convictions for this crime may be a good thing, and correct horribly misguided and/or grossly ill informed judgments by other participants in the political process.
The bottom line is that when one critiques the ills of our judicial system and political process that need reform and action, judicial activism may rate a quite low priority, even if you agree that all other things being equal that it is a bad thing.
Similarly, conservatives may view overzealous efforts of law enforcement officials acting in good faith to catch criminals, even if technically constituting civil rights violations, to be a quite low priority problem relative to problems like criminals not facing even the fear of criminal sanctions because they aren't caught because law enforcement isn't zealous enough in the methods that they use to catch criminals.
Recognizing that not all things that government officials do wrong are not equally problematic in the greater scheme of the political system is an important refinement to the usual default black and white assumption to political critics that all relatively frequent instances of misconduct by governmental officials are equal in the threat that they pose to the system as a whole's functioning.