More like DC's current continuity is a complete mess. And there are no writers who want to make things clearer.
Marv Wolfman wanted to make the continuity clearer with COIE, and he did it. I preferred the original Multiverse with Infinite Earths, but it worked. It made everything simpler: one Earth, everything happened there, end of the story.
The problems started when they tried to bring back the Multiverse, but overall 52 was handled pretty well.
The real thing that made DC lose any chance of continuity was the New 52. Differently from COIE, the New 52 wanted to erase what happened before. COIE tried to justify everything that happened before 1985 with plausible excuses, while New 52 was just pressing a reset button. And it went downhill from there.