Disagreed. The car would not even ask you to change lane if there is a car in your blind spot. Thus, your example is not a real life example.
Machine training is based on learning human behaviors under similar situations. Compare against the suggested behavior by the car is a critical step. Driver intervention is telling the car you don't like its suggestion. Repeat over and over again until a pattern is established. When your car prompts you to change lane, it means it believes it is safe. If you don't confirm, it should analyze the surrounding and try to understand why you don't agree...maybe it suddenly becomes unsafe, maybe too late, maybe the driver wants to go somewhere, etc. Or if you confirm and then you suddenly intervene because someone might have got into your lane at the last second, etc. So many possibilities. But it is a "teaching moment" for the car.
At the end, machine learning is not based on what you do. It is based on what vast majority of people would do under a specific scenario. This is exactly why Elon said it needed 10 mil driven miles before he can remove the lane confirmation restriction. Whether 10 mil driven miles is enough or not is up to the experts to decide. However, it is an unavoidable step. You may not like what it does at this time. New owners next year may love it because most of the problems may be resolved by then because we, the early owners, are part of the beta testing group. Remember, it is called Machine Learning....it takes time to "learn"
For those who don't want to be part of the journey, they really should not get EAP. We can go back and debate whether Tesla should have sold a unfinished feature, but it is a dead topic. It is what it is. We learned our lesson. At this point, we should wait for the feature to mature.