This type of thread usually doesn't surface until August or September and is almost as fatiguing to read as the "SkySaver Sucks" threads. If the OP doesn't like the top level at DL, he should go back to Air France. Why did he leave AF anyway? Were there problems there?
My reasoning to stay with DL after reaching the top level is to continue to accrue miles and to enjoy the perks, but I'm "only" a domestic flyer so YMMV. Why was I number 3 or 4 out of 75 elites on the upgrade list LGA-ATL for the past two Thursday evenings? Maybe because I continue to fly DL instead of scattering my miles between 2 or 3 airlines. Maybe MM's are a higher category on the upgrade list? Who knows. Only you as the flyer can know what's best when flying/accruing and which airline(s) to credit your miles to.
By all means, if the OP is not happy with Delta, there is nothing keeping him at the airline and should move to one that makes him happier.