Avex are the worst, the show is giving the artists free publicity but by removing the openings they're encouraging fans to download fansubs.
Licensing sucks, 10 years ago many J-Pop/Rock artists managed to tour the states bouncing off the recognition of their songs featured, for example FullMetal Alchemist and Eureka 7. In contrast during the past 5 years these new terms/contracts or whatever have hit Toei's properties hard. So what's caused this problem? Most people will simply say money and of course that is true, but it doesn't explain why some openings are featured and streamed on releases worldwide where as others aren't, so here's my guess:
Many of the artists Avex and Toei deal with compliment each other differently through brand recognition in Japan.
The Rootless don't have a huge following as a band, in fact they were quite new at the time, so 'One Day' featured on the opening benefits the band a lot more than the show.
On the other hand a huge artist such as Nami Amuro will benefit the anime a lot more than the artist by featuring 'Fight Together' during the opening, and Avex feels that their net worth is no exception to worldwide audiences.
After hearing about the deal with 'Kaze wo Sagashite', it really is like a big dirty business. The people in charge and making these deals within Avex and Toei (not just for licensing but across the board) are the real problem, and they have no shame because their face is hidden.