Well as far as I feel, you can't blame them for that.
It was a benefit that was too good to be true.
If you want to fly easyjet, ryanair or whatever airline, that's your choice.
But then get yourself a Priority Pass membership to get access to lounges.
(it's for free with an American Express Platinum card - no I'm not talking about the FB Amex Platinum card that they have in Netherlands...!)
In fact then lounges open up to you at almost any airport in the world.
I really think you can't expect AF/KL to pay for you visiting lounges that are not run by the airlines themselves but by third parties.
I would rather they invest money in upgrading their own lounges - and that's what has been happening, e.g. Crown Lounge Europe in AMS, although admittedly the non-Schengen lounge renovation is long overdue.