All in? HELL NO, nobody should go all in, regardless of age. Taking higher risks when younger--that's all well and good. But going all-in on anything crypto is a recipe for bankruptcy. I wouldn't even allocate 20% to crypto. You'd have to be crazy to go even half-in, and I say that as a person who likes bitcoin. A lot. It's just way too risky.
Provoking young people to focus on bitcoin I think won't be an effective thing to do. There are more important things to be prioritized first rather than bitcoin. Young people should focus more on their studies to get a good and stable job someday.
There's always a right time, they don't focus much because they don't have lot of responsibilities yet that will inspire them.
Young people loves to have fun and live an easy life, focusing in bitcoin requires you to consider it as your passion and when it's your passion you will love what you are doing and you will spend a lot of time doing things that would give you money.