Well Luckyned, the reason 'not everyone knows this' is , believe it or not, not everyone lives in the U.S., or a country where tipping is expected. Tipping is a by-product of a time when ex-slaves did menial jobs and the boss didnt want to pay a proper wage, so it was subsidised by tips.
Owning a restaurant must be great if you dont have to pay your staff minimum average wage and yet, you charge the customer full price and expect them to compensate your staff.
How does it make sense that the tip is based on the cost of the meal or drink? A $100.00 bottle of wine takes the same effort to open and pour as $5.00 bottle, doesnt it?
When I go to a restaurant here where I live, I order the meal, eat it, pay my bill, say goodbye and leave. No stress over the size of the tip, and , the service is usually always fine- the waiter says hi and smiles, chats and does it genuinely , without putting their hand out. Sometimes we might round up the bill, but not often.
I understand that its probably not going to change anytime soon, and so- good for the wait staff if they make out like bandits in the meantime.