My critique is that this adds additional disparity to the system, and even more inequity between certain classes and characters.
A low hit point character will likely always lose all their hit points long before they incur enough wound points for death (figure average Con. score of 10, giving them 10 wound points, unless they have 100 or more hit points, they are almost always going to reach unconsciousness before suffering enough wound points to die).
The same happens to a high hit point PC. See below.
The system says nothing about how quickly death can occur once the PCs are unconscious. A low hit point PC will be knocked unconscious with this system, way before he is killed. But, he can still die if he loses 1 wound point per round while unconscious.
A high hit point character probably has more of a 50/50 shot at whether they lose all hit points (uncconsciousness) or lose all wound points (death) first.
A high hit point character with a low Con is almost always going to die long before becoming unconscious.
Probably not. Think about the numbers we are talking about. A PC with CON 10.
First level PC. 20 hit points. Is he really going to take 10 wound points before he takes 20 hit points? The absolute minimum number of hit points that he has to take to get 10 wound points is 100. Most likely, it will be more than that.
10th level PC. 50 hit points (remember, WotC is lowering hit points). Is he really going to take 10 wound points before he takes 50 hit points? At most he'll take 5 and probably less (i.e. 3 17 hit point shots results in unconsciousness and 3 would points).
30th level PC. 110 hit points. In a single shot, this PC could theoretically take 101 hit points and 10 wound points and be killed (assuming monsters could ever do that much damage in 5E), but in reality, it's not going to be an issue. If it were, WotC would need to tweak the math a bit to make sure it doesn't happen based on their hit point model.
Granted, as the day wears on, wounds will accumulate. Players will need to have their PCs magically healed, or they might risk death. That's the point of a wound system. PCs might die if they do stupid things like go fight when they are heavily wounded and only have 2 wound points. It doesn't matter if the PC has a lot of hit points or few hit points, this is still a pretty dumb thing to go do unless it is absolutely required.
But, players will give their PCs decent CON (front line PCs will rarely have a 10 CON, usually higher), the players will go out of their way to bring some magical healing to the group, the players will go out of their way to try to find magic or items that give damage resistance. When it comes to RPGs, players adapt.
Anyway, I'm thinking the rest of your post is a bit nonsequitor since it was based on this faulty premise of how the system would work. As one example, a Dragon the size of a house at high level SHOULD wound a high level PC a lot more than a dagger wielding Kobold at low level. The PC is still human (or elf or whatever). The Dragon should crack ribs and break bones on a solid hit. It should burn flesh with its breath. The thing's a size of a house. But, the PCs have magic and skill to counterattack this. Although they are still human, they have amazing abilities. But, still human. Falling 200 feet should still do serious damage to them and the more powerful and deadly the foe, the more significant the wounds should be. IMO.
The concept that percentage-wise, a Titan should damage a high level PC the same that a Kobold damages a low level PC doesn't make a lot of sense from a plausibility standpoint.