Interesting. I grew up going to O's games until college when the Nats came to DC. I've pretty much switched since (a) DC sports are my home teams and (b) It's so much easier to take the metro down to DC than drive up 95 in rush hour for an O's game (although now I live in Baltimore). I still love the O's and have them as 1(b), but I can't pull for them as my home team.
Side note: I fucking hate the Ravens.
Second side note: Having your 1(a) and 1(b) teams finish last and second-to-last is impressive.
I think it comes down to how big of an Orioles fan you were growing up. Baseball was my #1 sport and Orioles were my first love, so to speak. Still mean every bit as much to me as the Redskins or any other DC team. I've lived in NoVA my whole life, Nats are clearly the more convenient team. And now they even have more promise (although everyone hated their owner too up until last year), but to me that is entirely beside the point. I dont choose who I root for based on convenience or promise, or for any other reason for that matter. Pretty much that simple. It would feel like adultery if I actually rooted for someone else. But thats just me.