I don't think it's necessarily people getting softer, but society getting tougher.
What I mean by that is the young adults of today got screwed up pretty badly by the previous generations, and the current state of society. Unfortunately, I don't remember where I read it, but I did read about how high school seniors are under the same amount of stress today as insane asylum patients twenty years ago. That's a lot of pressure to put on someone at such a young age, and the fact that they've been under that stress for twelve years doesn't help things either. Dealing with all of that crap for so long, it's a no brainer why the people coming out of high school today seem "softer" by comparison.
I don't think it's the younger generation's fault for being they way we are, as being put up against such expectations with an ever-growing list of requirements from school is a recipe for disaster. The stress may not seem so bad at first glance, but when it feels like over half of kids coming out of the education system suffers from some sort of anxiety, depression, or both, something is obviously broken.
Getting easily offended, temper tantrums, shouting at nothing, and not being able to take much more stress in general is, in my opinion, a side effect to the horrible education system and the continuing crumbling state of society in general. These kids come out on the other side, knowing something is broken, and wanting to fix it, take every little discomfort and make it out to be the reason society is messed up.
So now we have a bunch of young adults screaming about problems that are blown way out of proportion, desperate to do anything to fix every problem they've ever encountered. This isn't necessarily a bad thing, but there's always the vocal minority who will take it to the furthest possible extreme.
Heck, when people from older generations that were somehow "harder" start breaking down and getting their own share of mental health problems, there's obviously something very wrong. The main difference is that the older generations grew up in a much more stable environment, whereas the younger generations had to grow up with the chaos that is today. It led off to extremists that are promising a solution to the problem, when they're actually making it worse, and now we have a "soft" generation with a slew of mental illnesses trying to find their way in the broken world left for us by previous generations.