Yes, this is what bothered me most about the article. I see ideas just like jokes that a comedian or writer comes up with. Writers will all tell you they keep a notebook of ideas, meaning they're constantly capturing every moment they think they can fit in a standup routine or movie or whatever. I do the same as a computer programmer. Every time I think of an idea for an app or business, I note it, and in doing so I've developed essentially a background process in my brain that's always seeing if my sensory inputs have any good business ideas. I have a long list now and when I want to make something I literally just sort the list. And much like a comedian, I have no problem telling people my ideas, because I have so many of them I'm at the point it's depressing to think that I'll never live long enough to build them all.
I agree it's a skill, and hopefully over time you have a better understanding of what ideas are more likely to succeed. However, I don't think anyone out there can guarantee a great idea. How many times has Google failed again and again? Zynga is worth billions, and yet they're going to struggle to create another Farmville and they'll have difficulties staying relevant in the coming years. You can put the smartest minds on earth in a room for years with an unlimited budget, and they can't promise to deliver the next Facebook.
So, when you have that great idea, and you see it starting to grow, you better take good care of it. They don't come easy for anyone. That's part of the skill though, recognizing the good from the bad, and knowing when to jump ship, and most importantly, when to try again.