ASFs are illegal in some States, like Georgia, so they are a little bit harder to find in regular reptile shops. And they're also a bit harder to find frozen online too. There is no reptile shop close to me that sell them. So, if you don't have your own ASF source, you have to switch your bp to rats. This is why a lot of people prefer bps on rats so they don't have to do the switching.
I breed ASFs because I only have 6 snakes and they sometimes go weeks without eating. I can keep ASFs as long as needed and they will not outgrow my bps.