"These tattoos"? What specific tattoos are you speaking of? Shouldn't you have asked, "Why do so many young women get tattoos?". Besides, why is this any of your concern? Tattoos are for anyone who is 18 or older. If you are not yet 18, you have to be careful - you'll need to your parent's permission as long as you're getting an acceptable tattoo and aren't SUPER young (example - a 16 year old can usually get a common tattoo in a normal location with parental consent).
Tattoos and piercings are forms of body art and self expression. They are not "trashy", although, yes some tattoos are ugly and even pointless. They do not automatically make a person bad, scary, low-class or any other pointless insult that gets tossed around. People with tattoos (or piercings) also do not ALWAYS automatically have "low self-esteem/confidence" or mental health problems. Mental health issues do not go by whether you have body modifications or not. MANY people have them - with and without body modifications. Same goes for low self-esteem/confidence - many people with and without body modifications struggle with that. As*holes like you who bully/judge them do not help that btw.
Tattoos (and even piercings) also DO NOT severely impact your employment future. MANY jobs allow body modifications. Many body modifications can also be removed or covered during work if necessary. If a person would not want to date you or be your friend because you have a body modification, you should honestly be GLAD for that. Why? Because that person is a total LOSER. You are WAY better off without such a miserable, close-minded, judgmental individual. A TRUE friend would not give two sh*ts. A partner who truly cares and loves you would know true love means loving and accepting your partner ENTIRELY for their REAL SELF.
People get tattoos for MANY reasons, none of which are YOUR business. It is not your body, therefore, it is not your choice. You have no place judging others just such petty reasons. Learn to be more accepting of others, No one likes a judgmental jerk.