I agree both or all sides engage in self-serving agenda and bad policies. Nobody is perfect.

But it is hard not to see that extreme ideology drives the agenda of one or a few sides, while most sides are willing to compromise with reasonable, evidence-based solutions that the ideologists reject outright. It is irresponsible to say in that case that both sides are being unreasonable - that false equivalence promotes an unhealthy stalemate and gives cover to those who blindly delay progress.

Even when available date supports such a claim?

There are two ways to take it: the "everybody has been bad" GP used, and "the probability of any one event being X is lower than the rest." For the former, it would make sense to look at how guns are promoted as problem-solvers, and for the latter is worth discussing how group values make a person more likely to inflict firearm injuries. Utility vs. incitement, I suppose.