I address this upthread, but when you talk about how it's easier to bring people to justice easily in the world today, frequently that ease results from over-broad subpoena or bulk-collection powers. I think that warrants give much more freedoms to us as individuals, including the freedom to be private. What I would like to see the government systematically encouraged at every step to use warrants on criminality, rather than subpoenas for potential of criminality. So in that world, I think warrants need to be more useful.
This is sort of going back to what I was saying in my original post though. Encryption isn't a utopic vision of privacy, it is the middle ground. It's not harder today to catch child pornographers than it was before the Internet existed -- it's easier. The fact that we have encryption is being balanced out by the fact that we also have video surveillance, and remote exploits on Internet connected devices, and more payment tracking.
The FBI is not looking for a sensible, middle ground between privacy and bringing people to justice -- the argument they're making is, "if even one criminal escapes, that's too many."
Again, if we were in the opposite situation, if encryption did really mean that we couldn't catch criminals any more, then I'd be more inclined to say this was a complex problem. But the 'going dark' problem is largely a myth; with the advent of the Internet, it has never been easier to monitor citizens or access their data.
This is only a difficult question if it is genuinely a question between anarchy and encryption, but we're not even close to that being the choice we have to make.
You may not be of the opinion that every warrant should be executable no matter what, but when the question is put into the context of modern surveillance, it seems obvious to me that this is the FBI's stance.