I think it is very important to note that the entire concept of school choice (charters and vouchers) is not simply about "good" schools and/or "bad" schools. The idea of school choice should primarily be about parents having the option to place their child/children in a school that best meets his/her needs.
Let's use Providence High School and Clarksville High School as examples. Unquestionably, PHS has a higher ranking and would be called a "better" school than CHS given the way some on this thread have discussed the issue. If I have a child that learns better in a project-based environment that utilizes technology (New Tech - as is provided in Clarksville) than the environment at PHS, regardless of ranking, I would likely place my child in Clarksville Schools. Or if a one of our traditional public elementary schools in GCS offers more comprehensive services for my child with special needs than a local charter school, I will likely choose that GCS school over the charter school regardless of the "ranking." We even have a school of technology (Prosser) in our area that offers a choice for kids on the basis of diverse career and technical education course offerings that are there to meet the needs of kids who may not have access to those in their home high schools. It is not there to indicate that the high schools that send kids there are bad because they do not offer those courses.
I do understand that someone may choose a school because he/she believes that school is simply "better" than another, or because a one school corporation has a board that someone disagrees with, but agree with the idea of school choice or not, it seems that it should be about kids getting an education in a place that best suits them.