I only use the care package if I am also using black hat. As I can throw the package anywhere, then watch it and pick it up either on the way down or after it has landed still from cover.
When you play online and solo you have to expect anything can happen. You mainly got pissed at something because it is possible to do something. What do want them to change where you cant change the carepackage at all. The justification isn't going to happen because it's part of the game.
In hardcore I got killed and my carepackage stolen from a teammate a few times and you don't see me complaining about it. It's just a carepackage and play FFA if you don't have a team.
There are always more good folks out there than bad, the bad ones are just louder and more obnoxious.
That being said, I encourage you to play with a group as much as you can. I've been able to network and meet people online so now when I go on, unless its an odd time, there is pretty much always someone to play with. Doesn't have to be people you know, I have never met most of my friends list. Find some cool people, party up with them, throw them a friend request. They start inviting you, plus their friends... you make friends with their friends... it grows quick. A much better way to play, as you can enjoy the game and trust your teammates.
I understand, of course, that sometimes you have to play alone. When that happens, I would recommend using streaks that are not subject to the whims of teammates. Use streaks that you can control and that don't rely on your teammates covering you or trusting them not to take it. The Care Package has a counter, and that is that anyone can take it from you. Its a risky streak as it is the only one that can fall into enemy hands, and is an unknown. If you use other streaks, you will know what you are getting.
People do this beacuse they do not like you using the noob streak to get higher streaks than they can get in the game.
Either play with friends or do not use them or make sure you toss them where only a bh can be used to retrieve them.
Do anything but what was said and you will always have the chance someone will do as you say and they will not give a damn if you like it or not because they do not have too so they never will.
You said he changed it as you were collecting it? That is not possible. You can't re roll a care package if someone is in the process of getting it.