It’s still irrelevant. Other researchers did not find FAI to be an obvious approach, either. Holden is suggesting that SIAI could investigate tool AI as a possible safer approach. Eliezer’s response would make sense only if Holden had been suggesting SIAI should investigate the dangers of tool AI, in order to warn people against it—which is not what Holden was doing.
It’s still irrelevant. Other researchers did not find FAI to be an obvious approach, either. Holden is suggesting that SIAI could investigate tool AI as a possible safer approach. Eliezer’s response would make sense only if Holden had been suggesting SIAI should investigate the dangers of tool AI, in order to warn people against it—which is not what Holden was doing.