Be Brutally Honest - What is it that I am doing wrong that keeps putting me in the same situation?

My family and friends give me advice to "give people a chance" and to not be shallow. So, I guess I followed their advice but this going to sound shallow but I keep inviting the wrong people into my life. Within the past 2 years, I had made the mistakes of involving myself with four exceptionally mean, two of them were criminal type. I took the advice to be shallow, to give any guy who showed interest me. Now, I feel very stupid that I went out with guys I honestly never really found attractive and that turned out to be just as mean they were ugly. My friends and my family keep asking me why I went out with them in the first place if I thought they were ugly