Can someone please explain to me why it is wise for Humans to go Keep later than Orcs? Thanks..

ummmmmmmmm.... how do you know its exactly wise to go keep later than orc's with humans? and you ask as if there's a certan time to go keep/hold, not to be offensive but that question is a bad one

All Human players with a clue (Ag, Kith, etc.) say to go Keep late...

well, i'd guess they know why, i dont play human

you go keep late (typically) becuz u want to have solid defense and an expansion when you hit castle, that and it's hella expensive to get humans rolling in the late game unless ur just gonna pray that ur first few mages stop ur opponent in his tracks.