Hey Esteban, hope you're doing a bit better now.
Yes these things can happen in any big city, it would be naive to think otherwise. It's also naive not to realize it's happening, anecdotally, to more and more people that I personally know in BsAs. Things are cyclical and Argentina may well some day once more become an economic wonderland and a nice place to be, but if I'm honest, that's not going to be soon. I know in my 9 months living there I only saw it getting worse. Saw a couple get robbed by motochorros a half a block in front of me in my last few weeks there.
And while I don't love Argentina, and thus left it, I certainly empathize with people who do love it, or call it home and have to constantly weigh the situation against what they want the city to be. It's like LA in the early 90s or NYC in the 80s. I myself love Mexico, in particular Guadalajara, but based on friends' anecdotes, petty crime is getting worse there as well as the economic recession finally hits them much delayed. Makes me wonder if I would go back there. I'm not saying you should be careless and stupid anywhere, but constant vigilance day after day after day degrades quality of life.
As I said, I hope you're already doing better Esteban and that with more time you will be able to collect your thoughts and process everything. Yes, it was 100 pesos, but being robbed and violently threatened is more traumatic than even people realize. Please, stay safe all of you.