Except for those of us who got hooked early, I think science is a tough sell. There's little money, and the job market is flat (despite years of hearing about shortages of scientists), and there's almost no way the hours one puts in will pay off financially. That's the bad economic news.
Science is hard work, plenty of it boring, in relative obscurity, with a fair amount of isolation. So there is a social downside.
And if you are looking to 'change the world', being an activist or lawyer is going to look like a more direct route. Science is knowledge production, and one has damned little control about how or if it is used. So the impact of a single scientist is going to be limited.
Scientific superstars have a supporting cast that does the work and get none of the glory. So science has a sort of serfdom feel to it. (Worse, there is some sort of quasi-monastic bullshit that surrounds science, that makes people act like the serfs ought to be grateful for their squalor.)
It's awesome, captivating, enchanting and mesmerizing. I still can't believe that I am paid to do this, even if paid poorly relative to others who have put in similar time in academia. It was worth the years in school, and the postdoc, and the realization that, in my general field, I could have gotten a BS in chemical engineering and gotten both more money and more respect. But I wouldn't have the ability and freedom to really find things out. In my opinion, there is nothing better.