Why would you care if someone watched you take a shower or use the bathroom if you have nothing to hide?
1> Some people value privacy (unlike many of the younger generation that don't seem to know WTF privacy is, even).
2> Corrupt governments manufacture crimes (Is the US there yet? I dunno, but if I lived in somewhere like Russia I'd want as secure a phone as I could possibly get. I know I don't trust parts of the government as far as I can spit).
3> People commit crimes every day without even knowing it. I read once the average person commits like two felonies a month and has NO IDEA they are doing it. This is because there are so SO many laws on the books, both federal and state, some dating back to the 18th Century and while politicians are always in a hurry to make loads of new laws, they almost NEVER repeal older laws. Given the FACT that "ignorance of the law" is NEVER an excuse, would you REALLY want to bet your last dollar you've never committed a crime and that your phone could NEVER be used against you because you simply didn't INTEND to commit one? We're living in a country where marijuana is legal in several states now for recreational use, but illegal on a federal level. You're FRACKED even if you have a prescription and use it and the federal government decides to go after you since it's illegal on the federal level and considered to have NO MEDICINAL VALUE due to MORONS classifying it that way (see that Traveling Gnome guy running the justice department to see WTF you're really dealing with in this corrupt country).
People have gone to PRISON for having physical relations with their girlfriend in back-arsewards states like Georgia due to PURITAN type laws on the books for over a hundred years where things like oral are (or at least were) 100% ILLEGAL UNDER ALL CIRCUMSTANCES (married even) in that joke of a state and guess what convicted the guy? His PHONE!!! He had a video of it on it. Not fair? Too farking bad!!! What you THINK is "just" or "fair" or "right" doesn't mean SQUAT in a court of law! PERIOD! Ignorance of the law means NOTHING. You will go to prison and be branded for the rest of your life and not even understand WHY in some of these "hick" states!!! Do you really want to take the chance you may have broken a law and just hand yourself over on an unrelated charge/search because you went on vacation in a backwards state where something is illegal that you filmed with your wife??? It may sound crazy, but it's happened.
Do you think you have the right to backup your own software? The DMCA has never been tested fully in court on "fair use" arguments. The problem is that while you're supposed to have fair use, you're not allowed by bypass protection for ANY REASON including backups! Would/could that stand up in courts? Neither side really wants to fully test it since both sides stand to lose a LOT. But this is the kind of GARBAGE you have to deal with when MORON politicians pass laws they don't even FRACKING READ first!!!! (let alone understand)
Ultimately, privacy means NOTHING if we're OK with letting everyone skirt our privacy rights. The government doesn't need to know how much I drink an when I drink it if I'm not driving. They don't need to store my blood pressure 24/7 (to use it against me with insurance or some crap at some point). They don't need my fingerprints if I haven't broken the law. They'd LOVE to have everyone's! It would solve more crimes! It would also put you at almost every location you've EVER gone. Someone murders someone 2 years later and your fingerprint is against some wall you were leaning against when the room was laid out differently. People have been put to death with LESS evidence in the past. DNA is starting to reveal how fracked up some of these past convictions are. COINCIDENCE (also known as being in the wrong place at the wrong time) kills people every single day. Am I being completely paranoid? Maybe, but I'd rather be paranoid and not wind up on trial for something I didn't do or didn't know I was doing than "don't worry" and find myself staring at Big Bubba in my cell looking at me like I'm a piece of pie. The government convicts people for LYING yet that's all the government does to us every single day. It's not a crime for the government to lie to its own citizens, but it's a crime for us to lie to the government. Go figure. These are not people to put your "trust" in (just like the police that regularly shoot people they're supposed to be protecting because all too many are trigger happy cowards that shoot at the first "noise" they hear (like that woman that knocked on a police car window that she called to talk to them and the passenger cop shot her when he heard the knocking sound!!!) and ask questions while they're rigging the site to cover their butts).
Yes, you can TRUST law enforcement. They NEVER lie, never falsify reports, never plant evidence and never shoot anyone that didn't have it coming! Right. Why would anyone not want these guys going through their phones? They wouldn't plant evidence to win a case! They wouldn't LIE about it! They wouldn't shoot you if you're not a criminal! They'd never convict you and block evidence showing your innocence because prosecutors don't care if they win or lose, only if they get true justice!!! It doesn't hurt their careers to lose, after all! NOT!