What is/was the role of agamas in Chinese and Japanese history?

Recently I read/heard someone saying that the [agamas](http://en.wikipedia.org/wiki/%C4%80gama_(Buddhism)) are/were dismissed and downplayed in Chinese and Japanese Buddhism throughout history. I understand that Mahayana texts received much attention in these regions, but I wonder if the (presumably) lack of importance given to the agamas are simply due to them being neglected among the vast literature, or if they were explicitly disliked (for a specific reason?) or considered inferior, or obsolete. **EDIT**: Trying to be clearer: I'm looking for historical evidence for either chinese/japanese appreciation of the agamas, or evidence of reasons for chinese/japanese to neglect these books across the centuries.