Yes, I've heard the "ideas are worthless" meme, I just don't entirely believe it. Ideas are easier to have, so a bigger fraction of them are worthless, but that's not actually a good measure of the "relative worth" of ideas and implementations, precisely because the mechanics of producing them is different. Good ideas, e.g. actual market opportunities, problem-solving breakthroughs, are rare and valuable. Insight is valuable.

You can execute as hard as you want, but if you're headed in the wrong direction, the only good thing that's going to happen is that you're going to learn when ideas really are important.