I believe he was referring to an audience with God, not with other people.
You have good insight for one who professes non-belief. The practice of kneeling by the bedside isn't because of any sacredness of the bed but as the last audience of the day with God. We kneel as we ask his His presence to thank Him for his bounty and ask His continued Blessing and Grace.
It is an act of supplication and the location is simply due to what follows--sleep.