The way DC chose to do things has nothing to do with how Bad Robot chose to do things.
Especially since DC repeatedly wipes out its entire continuity, ALL THE FUCKING TIME. They don't let three or four years go by before they do some damned 'Crisis' that resets everything back to square one. And they keep doing it
. There was Crisis on Infinite Earths, then Zero Hour, Infinite Crisis, Final Crisis, Flashpoint, New 52, ad nauseum
. So they don't have the chance to build up anything meaningful anymore, because we all know they're just going to reset the whole damned thing again.
Nothing about the Abramsverse is even close to this level. That timeline can coexist with the prime one; can't say the same thing in DC, not by a long shot.