@ kick the tires: And would that be ATC in general? If so, maybe you should start realizing that ATC also isn't the enemy here. I can't speak for the Spanish cases, but there is almost always a viable reason for any decision from ATC-side you don't like.
The Spanish ATCo is following the rules his company sets, the guideline is to let flights depart as close to there CTOT as possible to get the best effect 'Flow-wise'. The -5 and +10 are purely to give them a bit of room for sequence purposes.
Same applies to your side, lots of pilots reducing to 250kts below FL100 even if i tell them to keep a certain speed. (In class A airspace this is) Most of the times they won't even inform me, wich can be quite a pain in the bottom if you are sequencing tight.
I understand that you (pilots in general) have to follow SOP's, but so do controllers. And yes there are a lot of pilots who do keep the speed up untill advised even if their SOPs state otherwise. But there are also a lot of controllers who will go out of their way to get you airborne at CTOT -5. But this is not anything that can be expected, or demanded.