For a long time, the weekly tome limit has been in place to keep people playing daily/weekly content, but it just doesn't really make much sense anymore. You subscribe by the month, and get a lower charge for more months at a time. How does forcing people to play week to week just to keep up their gear make sense?
Furthermore, it's always limited people to one or two classes to "main." The game has more than 20 classes. Let people actually work towards their gear at their own pace, let them play as many classes as they wish without arbitrary time gated gear and tome restrictions. Just get rid of this old holdover of 450 tomes a week.