This has become a cliche, but is nonetheless valid: it's not their job to legislate. Right-wing judges certainly legislate at times, but not to the degree that liberal judges generally do.
Nevermind the natural inclination of liberal judges to be too lenient in sentencing.
I do have to say, though, that the single-worst bill Trump has signed is deals with criminal justice reform. It was obvious pandering at its worst, and it is placing people in danger. It appeals to naive, dopey people who do not have to live next to the dangerous convicts they are releasing, from spousal abusers to dope dealers, and worse. Shameful, yet predictable.