Instead, imagine someone who has found a "market opportunity" (not "an idea": everyone has ideas, and assuming programmers somehow don't have enough of their own to work on is part of what makes these kinds of e-mails insulting ;P): in this case, "the suit" is someone who has the knack for turning ideas into formal/defendable contracts and closed/agreeable business relationships in the same sense that you or I have the knack for turning ideas into stable prototypes or scalable production implementations.
I personally then love dealing with "the suit": I love bringing my ideas to him, and I love seeing what he does with them; I love not having to worry about that particular aspect of building a business that I often find tedious, frustrating, or even intractable (a similar feeling, I imagine, to how he feels about what I do).
From this perspective, I can't imagine any of "the suits" that I know (and I now know a bunch) sending an e-mail like the one in this article: it doesn't have any of the properties I'm used to "the suit" having found fascinating about these kinds of problems. (Of course, this e-mail is probably not verbatim, summarized through the veil of this blogger, and I might be reading a bunch into it based on your response.)
I can thereby understand feeling the need to ask someone like this to go off and do tasks like "try to find a customer" and "can this be done manually", but somehow I feel like this is really just trying to tutor the person on the other end to see if they have basic business sense (the same kind I imagine you have): when "the suit" contacts you, you will know it ;P.
Now, you may also have been contacted by many such "the suits" already, and disliked them: sometimes, these people's slavish devotion to business opportunity and formal agreements might cause them to be as alien as someone with a slavish devotion to process and repeatability (as many programmers have) is to a "normal" person.
Alternatively, you might not have been inspired by the kinds of markets they attack: they might not seem world-changing, or challenging, or technical enough to even involve you; but the property of "the suit" that gives him that title is that he didn't just have an idea: he is thinking about how all the people fit together, and is fully intending to be the person who makes it all happen.
I thereby encourage everyone to get to know a real "the suit", get to know his friends, and try to see how they live their lives and why they do so: I think you might be pleasantly surprised. That said: you might wonder how to recognize "the suit" if you feel all of them are like this e-mailer (by which I really mean the stereotype of the guy who has a lightbulb go off in his head, brands himself "the idea guy", and tries to find "the programmer").
I might recommend finding someone older (although my go-to "the suit" isn't), who honestly likes wearing suits (;P), and weirdly knows all of the lawyers in town; he probably also knows about every business operating nearby (and exactly who funded them), is friends with the guy who owns half the buildings, and is respected enough to be invited to give advice to others at local business plan programs.
You might, then, be surprised both at how useful these people are, how unimportant it might be that they are currently technical (although enough geekiness in their past to have at least some feel for what is technically possible is quite handy), and at the same time how the people sending these e-mails are more like a guy who just learned PHP last week trying to start a business with the CEO of General Motors than someone we should be up-in-arms about.