Most of what you see are folks with roommates. I luckily moved to DC as an IT engineer, so my starting salary was significantly higher than most people my age, and lived with my GF, so I guess that counts as a roommate as well.
Don't let the 'cost of living' mantra get in your head. Other than rent or mortgage, most other things cost relatively the same as other places, give or take. Home ownership is doable. You can get an FHA loan for 3% down. 3% down on a 360k house is only 10K + closing costs and fees. It's totally doable. The trick is, having the right job, or right field (since jobs can be lost), and flexibility in both where you want to live and where you want to work. It's 100% doable.
Where you see people having issues you'll find them refusing to give in on something and being stupid. IE - want to live in DC? You're either going to have a roommate or spend significantly more than if you're right across the Potomac. I watch people do this constantly; they want to tell people they live in DC, but then complain they have no money. Want a nice mcmansion? You're going to have to live out in Loudoun or further, have a nice job, and you're likely commuting an hour+ a day. Want to live closer? You're spending more, and you're not getting a brand new house. Adjust. Want to live alone? Gotta cut back on other frills.
If you're living at home right now, and that situation is working for you, run with it. If you're working 40hrs, plus out doing things, how much time do you spend at home realistically? Not much. Pay off your loans and debt and run with that while it's still an option. You're not missing much. Granted...that's easy for me to say. My parents are 3 states away and I bought a house when I was 25 because I was tired of renting, but you better believe I cut back on other things to get there.