In 1915 when a discovery subpoena goes out for all records relating to dumping dioxanes in a river, the company legitimately unlocks the filing cabinet and hands the files over. They don't get a key to the executive washroom or the telegram private code directory (unless that was in the subpoena) or the complete customer list or really pretty much anything but the paper files relating to dumping dioxanes in the river.
In 2015 when a discovery subpoena goes out for all records relating to dumping dioxanes in a river, the company freaks out because if they hand out "the" public key then both the .gov and any .com they're affiliated with and probably individual theives will pown every VPN they ever had and ever will, and all their records of every sort so "oh no we can't hand over keys never to no one".
When you look at it from that point of view, the abject failure of IT and IT companies to properly handle encryption is by no means any reason for the judicial legal system to be inconvenienced. In 1915 no judge would have tolerated a response like "Well we can't give you the dioxane pollution paper files and telegrams because then criminals would pown our company because we're incompetent at IT"
The other part is sociological. You may hold that phone in your hand, but its not yours, and using it is as dangerous as talking to a police officer or government official or hacker. Its not your phone, never has been, and any illusion to the contrary will result in tears. Ditto a site on the internet. Government protection of privacy assumes the privacy ever existed in the first place, which it doesn't.