Earlier quoted context omitted.
The difference in all the examples you’ve given here is that none of the people involved are journalists. If you work on PRISM leaking its existence does nothing for your career. Quite the opposite in fact. But if you work for a newspaper and leak a massive story it’ll be very beneficial for your career.
The journalist most famous for leaking the Panama Papers died under mysterious circumstances. And almost nobody is aware of her name or even what's inside the Panama Papers. How many famous journalists can you name? I'm not saying there aren't journalists that want to do good work and become famous as a result. But despite their efforts they're mostly fighting a losing battle.
I’m not sure how that’s relevant. Ask a dozen people on the street who John Carmack is I’m sure you’d get a lot of blank faces. But if he walked into a dev shop looking for a job I think he’d probably get one.
Of course breaking a massive story is going to lead to you being well known. Perhaps only within journalistic circles but in the context of your career that’s the only thing that matters anyway.
(and to answer anecdote with anecdote: Woodward and Bernstein. Both have lived to ripe old ages, too, for what it’s worth)