Well, I guess I can somewhat agree with you, then. If I see this as just the rough way to get medical science to progress faster, sacrificing a short-term benefit for a long-term larger one.*
The problem that I see with this is that it will give more means, without assuring that those means will be used for the good of everyone in the future, whereas the UHC approach takes a step in this direction. In other words : let's say you continue with the current system. When we've cured cancer, cured AIDS, and when every bit of effort put into saving a billionaire from an obscure sickness can save a thousand lives where people still die from cancer and AIDS, then why wouldn't the richer half of the country use this - now flawed - argument again ? Where is the line drawn, where you have to switch from long-term planning to actually helping people ? More change would have to be brought, and quicker, upon a society used to a very different thinking, and you can't be sure the right decision would be taken at this point. In light of this, maybe socialism takes little steps, but it takes them in the right direction.
However, you can't actually judge something according to this kind of very abstract thinking because you would need to get into an awful lot of technical details to have an idea about what decision would ultimately be better. I'm just saying this hoping you haven't already considered it.
*Knowing whether it is the case in reality, according to numbers and statistics and other stuff, is another problem, but I am not that interested in it, so let's say you have a point too and leave it at that.