[hnfong]

They actually do have to, in a sense.

Being the only non-democratically elected branch of government in a democracy, the courts don't enjoy direct approval from the people. So while the structure of the institutions seem to give them power, their authority ultimately hinges on whether people perceive their decisions fair and just.

When courts make unpopular decisions and can't explain why, there's always a risk of some constitutional crisis. If courts keep making decisions that they can't rationally defend, at some point their authority will begin to erode. (And if you followed the USSC rulings in recent years you might start to understand why. Maybe the resentment not yet directly targeted towards the courts, but those decisions did add fuel to the already divisive politics in the US.)