I work for Borders so maybe I can shed some light on this as well. As a company, we're definitely not cutting back. It just goes in waves and depends on the volume that the individual stores sell. My store has a pretty big manga selection because it moves (in that people come in and actually purchase the books). I know we have all of Blade of the Immortal, but it varies store to store.
The best way to get your store to carry is to continue to purchase. If you only go to the store and use it like a library and never actually pay for your books, then they see no reason to carry them (and I'm not saying you do). Let's face it, Borders is a retail entity and does things to make money.
If you want something that your individual store doesn't carry, there's an in store guarantee, which means that if we don't have it (and it's still in print and available through the distributors) the store will get it for you (and usually ship it to your house for free. If you're a rewards member there's almost always a coupon, which makes it comprable to prices you'll see online especially for new releases. Several times during the year we also have "Buy 3, Get 1 Free" sales, which are an awesome way to catch up.