I disagree completely on this. For one, users aren't aware that using iCloud means that Apple has your decryption key and can thereby read and share all of your phone's data.
And two, opt-out is a dark pattern. Particularly if you surround it with other hurdles, like long click-wrap and confusing UI, it's no longer a fair choice, but psychological manipulation to have users concede and accept.
Third, as it's hinted, smarter criminals, the ones the FBI should actually worry about, will know to opt-out. So instead the vast majority of innocent users have their privacy violated in order to help authorities catch "dumb" criminals who could have very well been caught through countless other avenues.
disclaimer: I just read Bruce Schneier's "Click Here To Kill Everybody" after the pipeline ransomware attack, and these points come straight from it.