For the same reasons as stated above. The Orioles own the broadcast and refuse to allow it to be shown outside of there domain. Any of their games will be blacked out in areas not in the Baltimore area.
Do a search here or at DBSTALK.COM to find out about the sports pack. Most or all of your questions will be answered. There are some reasons to get it, but not if you want to see out of market games. If that were the case everyone would get it. That is why there is the MLB package at Direct, or the NBA and NHL packages at Dish.
The sports pak is a waste unless you want to get stuff that you can't get in your area like some college stuff. I use to get it to watch ECW wrestling and some auto racing and outdoor shows. Also, when E* first offered it they had so many bugs that there was a pro game in the clear every night whether it by MLB, NHL or NBA.
This package is still good if you live in an area where multiple pro teams claim you as theirs.
For example, Buffalo NY where multiple teams claim them and some areas of PA where Baltimore puts a claim in as well. This paclkage will give you access to every team that claims you assuming that they're on different RSN's so some people are lucky.
I love high school football, yeah, college and pro too. The sports pack has some really good high school football games from Florida, Texas, New York and the like. I keep the pack for that kind of stuff.