Why the hate for flights that are not DL-coded, but are operated by DL, in the context of the current JV?

I've been a NW elite and I got spoiled by the seamless integration with KL. I know how good it can be, and it can be very frustrating to experience what the DL/KL/AF JV isn't.

Examples:

• Seating issues (widely known on this board)... the ability to choose seats on partner flight or on DL's own flights when sold by a partner (a KL or AF ticket stock).
• Medallion upgrade issues: if you're a DELTA medallion on a DELTA domestic flight, if the flight is a code share you are not eligible for UGs. Not cool.
• Promotions: I got the 75% FO mileage bonus promotion. It's only good for DL marketed/operated flights. NW never excluded NW flights from promos because they were sold by a JV partner. I find it ridiculous that a DL-operated TATL flights that part of the JV and that generate revenue for DL are excluded. Furthermore, NW always included KL flights in their promos. I find this to be a very anti-JV attitude, instead of marketing the JV in general (e.g. TATL flights on KL/AF/DL or even DL flights sold by KL/AF/DL) they exclude their JV partners.
• Earning mileage: discrimination between DL-coded and AF-coded flights, on equivalent fare classes (fares that are the same price)

Is DL inching towards a stronger partnership for an enhanced customer experience? ("inching" may be an overstatement... maybe nanometering) Or is all hope lost in this regard?