Hint: You are more likely to become to become an executive if you have a previous good track, and having one insignificant failure on your belt, is not.
Come in the valley: 1. if you want to seriously start anything that is very technically challenging. The top talent of the world is here.
2. If you want to join an existing company and learn a lot. Then you can move in your country an open whatever you want there.
3. Scale up. If you have a decent idea, a working product, and some good traction, but you need to scale up (more funding, people to work on it, etc).
I am currently very actively wondering if the access to all those smart people is worth risking the potential loss of perspective. (I wouldn't have to try and build a design community out there, I could just work and network.)
Another thing to consider is that (technical) standards are higher here. Be prepared for a 'big pond' experience. Yeah, salaries are higher here, but so are expectations. If you were always the best person in the office elsewhere, it might be something of a shock to come here and find yourself closer to average. But that can be a good experience, too.
Of course, you are talking about executive roles, so probably none of this applies to you.
It's not surprising to hear somebody in a cafe working on their pitch or sometimes actually pitching to an investor.
For me, it's like watching a football game in the stadium as opposed to watching on TV.
After being a spectator, it motivates you to someday play the game too!
I don't live in Silicon Valley, but I would imagine that while there are lots of these more of these opportunities floating around, there is a lot of competition for them too. That said, if you want to be a movie star, go to Hollywood. If you want to be in musicals, go to New York. Country singer, Nashville. The same logic goes for startup founders and Silicon Valley. There are bound to be more resources and like-minded people there than most other places, and that's where the venture capital lives, too.
I just saw your profile, says you 'document' your experiences. You have a blog?
Besides networking, there also seems to be a ton of educationonal opportunities like seminars, meetups, and conferences of the quantity and quality that you won't find anywhere else.