There is nothing wrong with the metro. Some of us locals are snobs about certain metro lines. It's just the local smack talk. For example I live on Capitol Hill, and I talk smack about the 'new' silver line that goes nowhere. And I am too good to ride on the cattle train they call the redline. Don't listen to us. The DC metro is seriously awesome. Virtually no crime, clean, cops everywhere, and too expensive for homeless people to ride it. I have never felt unsafe on the metro ever. Weekends it is full of tourists. Weekday mornings are a little claustrophobic and there is metro etiquette that you will get wrong.
One rule to remember: when on the escalator, stand on the right and walk on the left.
My wife hasn't driven in 4 years and loves it. She rides a section of the redline everyday.