It has nothing to do with being weak, it's that once our crazy radar has been triggered it is less of a headache to get rid of the person than to continue to engage the crazy. You display irrational tendencies quickly and it is a red flag to them and they remove themselves from the situation, it is as simple as that. It isn't a sign of anything about their ability to be a partner, what it shows is that they know what they want and the behavior you're displaying is not it. If somebody is showing you a behavior that you dislike in the early stages of getting to know each other what will they reveal as they feel more comfortable with you? They are under no obligation to stick it out and see if you'll change. Just move on