You carry concealed in MD because you have to.Where I live in Maryland (Annapolis) a lot of people think firearms are an evil that must be eradicated. Now, I'm happy to have a civil discussion on the matter with anyone that isn't a zealot - heck, I'm even willing to do that - but I would prefer to choose the time and place of those debates/discussions. Wearing openly invites being treated like a leper at a minimum and confronted with angry words on my life choices and attracting all unwanted attention.
I carry concealed because I can legally and I feel competent in doing so. I wouldn't dare tell anyone what's best for them unless asked but for me personally I also see no upside at all to carrying openly.
You see no upside because you have no choice.