Suggest you humble yourself a bit and act like the low man on the totem pole that you likely are. You know, act like the student, not the teacher.
If you do that, you might find that some of the grizzled old, bitter, boomer veterans are more than willing to help you out and help you along in your career.
When I started in the oil patch, my goal was to one day be able to say "Kid, let me tell you something about . . ." just as it was said to me.
That would mean I had actually accumulated knowledge worth passing on.
You ask "Why so many negative stereotypes about younger employees? "
The answer is respect and humility. Even when you're in the right.
Let it be known that you want/are willing to be "mentored" and you'll have plenty of backers going out of their way to help you.
Let it be known that you're the smartest guy in the room (even if you are) and you'll have plenty of people wanting - if not hoping, perhaps working - to see you fail.
Take it for what it's worth.