My guess is that because of the Knox situation, people are not following best practice when it comes to switching from Android 4.2.2 to Android 4.3. This would normally be to flash the stock. 4.3, Samsung firmware first before flashing the new ROM. This would give a firm base line for custom ROM flashing. However, in the hope of dodging the Knox bullet, I feel that many of them have been just flashing over the top of 4.2.2 and hoping for the best... with predictable results.