I don't see it as sad at all. Limiting the target audience is a perfectly legitimate way of starting an MVP business. When they copy the idea, they apply huge amounts of process and local business knowledge (local laws, relationships, etc), which they then sell for profit. Everybody wins.

I'm surprised they're not revered, given the popularity of the claim that ideas aren't worth anything, and that it's about execution.

I guess the problem for a lot of people is, sometimes the samwers clone the execution too. In some cases even down to typos in the HTML source

html and css source is not execution. Getting distribution, partnerships, sales, etc. right is execution, especially since they don't clone tech-intensive companies (or at least not the tech-intensive parts)

why is that sad? Silicon VAlley claims ideas are worthless and execution is everything, until someone actually copies their idea.

I think there is a difference between copying an idea and improving on an idea.

A good example of this would Google who made a better search engine even though the idea of a search engine wasn't an original idea in it self, they just made a better one. Hence; execution.

Well, I'm not Silicon Valley. I just don't like the concept of simply copying someone else's idea as a business model, because you're piggybacking on someone else's idea, and it's uncreative.

I wonder what is your opinion about barbers, shop-owners, car manufactures or basically any business outside of the internet. I think that there's big difference between copying the business model and the product/service itself.

It's more copying a company, its business model, idea, everything down to the fine details that bothers me. Not so much copying a business model or an idea.