I'm 35, and I'm perfectly able to engage with the thought process behind the opinion, no matter how radical. All they want is to be treated with respect.
Contrast with “real adults” who e.g. continue to trash the planet because they can't even think of slightly decreasing the amount by which they enrich themselves. Those I don't respect. They are the real radicals.
If a 15 year old says “so much good can happen when a few billionaires kick the bucket”, I'm right there with them.
Most teenagers I know are leftist, so you're right in that most aren't like that, but you're very wrong about insinuating that I'm wrong.