Districts can use a blended model because they have more flexibility in how those students are counted. They could, for purposes of the funding paperwork, be brick and mortar (BAM) students with the online portion as supplemental. Or the students could be recognized as being fully online although they still come to a BAM school for a certain number of days each week.
Charter schools don't have that flexibility because they operate under contract with the district authorizer and have only a finite number of students. In other words, there's less places to hide students.
State policy was created (as much state policy is), in reaction to various situations that happened rather than sitting back and asking what was best for the individual student. It doesn't take a rocket scientist to figure out that a blended model is better for most students. Whether students are young, high risk or simply extremely social, having the interaction of an adult to explain difficult lessons and help them stay committed to the task of independent learning is always a good thing.
So rather than acknowledge the benefits of blended learning, Colorado state policy provides for "learning centers." These are basically private schools that use an online curriculum. Online schools can also have "drop-in centers." Although this isn't defined in statute, it means that online schools have a physical location where students can come for additional assistance. There are even students who are "strongly encouraged" to come to the drop-in center on a regular basis for additional help. But they cannot be "required" to come to the center at a specific time or for a specific length of time. It's all in how it's worded for the student and a "wink-wink" from the teacher.
One of the best things about blended learning also makes it the most confusing. That's because there is no clear definition of what it is. It's a significant variety of models along a paradigm from fully online to fully BAM. But that's why it's so ideal: it meets the individual needs of students in a variety of ways.
It's certain that this year's General Assembly will be talking about online learning. If they were really interested in doing what's best for students, they'd be talking about how to provide for blended learning.