For my part I'm not going to try to pitch Fate to anyone or construct a marketing pitch for it.
There isn't one. Or rather, there isn't just one.
If Fate is a good system for a story my friends and I are trying to explore, I'll tell them so, and I'll tell them what makes me think that.
In my case, it didn't take much, because they recognised it.
We enjoyed D&D 4e's setting, but for all of us, combat was the least interesting part, and the rest had very little mechanical support. Combat was fun, but a bit of a slog. When we found a system that didn't care all that much about combat as a means to success, and provided enormous sweeping support for loads of other stuff we were interested in, we were immediately interested.
For me as the GM, I was also attracted to Fate's low amount of prep. D&D is something that involved a lot of pre-planning, and I was spending so much time on the prep I couldn't even let them dive into the proper campaign first. I started them on an introductory island which was kinda rushed. Fate on the other hand allows me to come up with just about anything exceptionally quickly, so prep is minimal and fast. It embraces not knowing everything, and not having everything planned out.
I can fly by the seat of my pants so well that one night, just to find out what it was like, I ran a session with no prep whatsoever. We had our setting and characters established. We sat down together, I told them to tell me what kind of story they wanted that night, and I ran it for them. We went with a story where they were hunted by some enormous beast that was supposed to be imprisoned, but they'd found its cage busted open.
It pursued them across the countryside, over a chasm, destroyed the bridge they were on, and they eventually built a log trap down the side of a hill and triggered it, killing the thing.
Aside, nowadays, I'm at a point where I could portray that pretty differently too - like the thing not dying, and also being portrayed as, perhaps, pitiable, and the harming of it regrettable. I could introduce a lot more subtleties into the mix and make it far more engaging.
And I also know that giving a thing 4 stress boxes will still make it pretty trivial to annihilate, and that in such a situation there's many different options available than saying they killed it.