Cropduster, it's not that they don't want you to "know about it", it's that they don't want you troubleshooting with a planeload of passengers in the back. That's been known to end very, very badly.
Two examples:
https://en.wikipedia.org/wiki/Alaska...nes_Flight_261
https://en.wikipedia.org/wiki/Easter...nes_Flight_401
There are also suspicions that troubleshooting a problem played a part in the recent Lion Air crash (now that the CVR has been found we should know more before long).
BTW, since engine oil quantity is displayed on primary EICAS, what could you have learned about an oil leak by checking the ENG page?