You can earn money from agility (amylase crystals), but anyhow, jagex keeps it at a high ban rate because many of the high money p/h methods require high agillity (be it through direct requirenments or quests). So why control the methods themselves when you can ban most of the people while they train to bot?
I use another "bot" that has way lower ban rates than this, and i still get ocasional bans while training agillity, even though i train the accounts to 50 agillity in 24-48 hs from creation.