The biggest problem cryptocurrencies will face before becoming mainstream (IMO)

So let's say that the current establishment (banks and governments) accepts the cryptocurrencies (I'm allowed to dream) and suddenly all our money is under our control.

I mean, I'd love to see that, but I see a major problem in all that and I can't think of any solution.

I'm talking about blue-collar crimes.

Check this out - Britain's first Bitcoin heist as trader forced at gunpoint to transfer cyber currency

This was the first reported case in the UK, but this is old news in many countries. I always knew about this problem but now that it started happening even in rich countries, I'm terrified of what will be of third world countries.

I currently live in Brazil, and I'm afraid to even whisper the bitcoin word. Every time I talked to friends (always in person, never online) about it, I could notice stranger eyes immediately turning to us, prying on our conversation as if we were millionaire aliens. My maid (yes it's a common thing here and they are poor, very poor) once heard me talking about it (no numbers, just the name) and I could see she was breathless, had dilated pupils and increased heart rate. I'm not kidding!

But back on the subject. Nowadays the majority of our money is in the banks, which have daily withdraw policies to prevent this kind of robbery. If there's a daily limit, nobody can steal everything you have from your internet banking app. But with crypto currencies there are only a few options to keep your money:

• Exchanges: OK, fine, exchanges are meant to be used for trading, not exactly a wallet, but anyway, it's the riskiest option since you are also risking your money to hack attacks.
• Hardware wallets and cold wallets: You can keep your money somehow safe with it but a robber can either force you to give them to him (along with your password) or just force you to connect and transfer your coins. Plus, it has the major disadvantage of keeping your money unusable. You can't use this kind of wallet to pay for anything.
• Hot wallets or online wallets: This is the only option if bitcoin is to become a mainstream payment method. Most likely an App installed on people's smartphone. It's the dream. The fastest and coolest payment option ever created. BUT it's also very risky. Let's ignore the fact that some people don't even lock their phones and that most use patterns or easy passwords/pins. This will happen, people will lose their devices and lose everything in minutes. But I consider this just natural selection. The main problem I see is that people will be able to rob ANYONE, ANYWHERE. Even bullies at school will take our son's bitcoin instead of just their food. Kids will be kidnapped to force the parents to transfer everything IMMEDIATELY. Armed people will rob an entire bus in minutes! And the possibilities are infinite.

Are you following? Can you see how impossible it looks like for cryptocurrencies to become what it's meant to? Or am I missing something here? Because I gotta say, this is the biggest FUD about cryptocurrencies for me.

Please, let me hear what you have to say about it. Do you think there will be crypto banks? Hot wallets with daily limits? Keep in mind that we need something that any grandpa(ma) with basic tech skills can use.

Cheers!