You're probably missunderstanding the meaning of macro and bot. A macro is just a linear input queue that is triggered when the player presses a key. A bot is a script that works without the players interaction and usually fetches pixels from the game to know what action to do next(yes one pixel is enough for most purposes).
And sure SE can just ban you if they think you bot. But they can get intro trouble if you sue them after getting banned just 'cause they "think" you botted. I think a GM already mentioned it. It's better not to ban a few botters than banning them and accidently banning someone who didn't bot.