Speaking as a teacher, having a quality curriculum to implement means I can leverage my time to give specific feedback, intervene, examine progress, collaborate/reflect…
Don’t make us develop our own instruction. There are much wiser uses of our time and talent.
Speaking as a parent, if you honestly believe that making sure teachers have decent curriculum is evil, then your own kids aren't in public schools. Once you see what kids learn, and how widely it varies from classroom to classroom in the same building, you can never unsee it.