There were a few reasons why we decided AC was a better option for us.
First, we are primarily Windows based District. While we allow Apple devices all of our backbone is Windows based (Active Directory, etc)
Second, we are only allowed one Apple ID per school at the district level, making MDM solutions more cumbersome to implement, especially since we have purchased applications that are tied to different Apple IDs. Apple's VPP is broken as it is (not able to get codes from stolen/broken devices) using MDM with paid app's is even more of a headache when these licenses get transferred to other users
Third, While Meraki and Apple's Profile Manager are free MDM solutions, we found that are hard to navigate and in Profile Manager's case is missing features that other pay for MDM's have or in another case, features that even Apple Configurator has (like renaming Devices).
Four, and to piggyback off number 3, paid MDM's like Casper seem to be on average better than free MDM's (you get what you pay for right?) but those MDM's are a per license purchase. Meaning you pay like $8 per iPad you want to manage and schools in our district are just not wanting to flip that cost as of now.