This isn't an accident. They know what they're doing.
Every municipality tries to do this to the extent they think they can get away with it because it's an end run around your property right. There's all sorts of residential exemptions and precedents and case law and courts and politicians tend not to be in a hurry to screw homeowners because there's tons of them.
By classifying you as commercial it gives them a) all sorts of capricious authority to micromanage the pettiest of details and/or force you to expend money with no recourse except "haha, sue us peasant".