Probably because they've speeded up their production of volume releases (and are up to volume 45) and want people to buy it, rather than read it online now that they are getting so close to the end. And they are giving free access to the subbed version of the Final Act, so no doubt they feel they are taking care of the fan base.

It's not quite the same, but they do own the rights to InuYasha and let us have access to it for a long, long time. Most American publishing houses would have been slapping cease and desist orders a long time ago.