This is what was stated to me - could be a discretionary policy. Of course most of us value lounge access at over 1000 miles, but this is the amount EK has deemed to be reasonable compensation to Silver members for denying us the privilege. If you are flying at an 'easy' hour at DXB when lounges are reasonably free, EK could keep us slightly less miffed by offering alternate lounge access in T3 or T1 to Silver members in lieu of the miles.
Most posters here are probably Gold+, but Gold status is increasingly difficult to get on EK flying exclusively Y (I make 7-8 MAA-Europe RTs/year), with the saver fares and all. And if you fly J/F, you get most status benefits anyway. I suspect there are a lot of Y flying silvers like me who value the Silver privileges and choose EK for that reason. One benefit, the op-up, is becoming increasingly infrequent recently. Take away lounge access (I will not consider doing the midnight transits at DXB zoo without it), and I'd much rather fly 9W - which I'm doing next week.