I get the attraction of charter schools, but I also get the argument that they syphon funds and cherry pick students with motivated parents from public schools, which cannot pick and choose what students to admit. How is anyone surprised that data shows charter schools do better? They have their choice of students. This skews the data from the beginning. Then to make matters worse, the public school is left with students expected to underperform and fewer funds to deal with that population.
If you want to prove that charters work better, randomly assign students in a blind fashion so that they also must deal with unmotivated families and disciplinary issues. Do that for a few years, then compare the numbers. If charters are still ahead, at that point, there should be wholesale change. But for now, charter vs. public is not an equal playing field.