The ability to look at a vaguely specified problem and say "Okay, here's how we're going to attack it, and here's what we need to build to have something that works" is a very valuable skillset, and not everyone has it.
Now, remember that "finished" is not the same as "launched". Usually, my responsibilities continue up to the point where we can get a product into the hands of users and train the people who'll be maintaining it after me. But there's a fairly large role for maintenance programmers, people who are responsible for little tweaks even though the system is mostly working as desired, and if you're a Starter, there's no reason for you to do that work yourself.
I have had a similar position.
My firm is hired to implement concepts as working products. I first help the clients decide whether their idea has legs and help them refine the vision. My team builds out v1 over a period of months, and then we generally hand off to an internal team or another firm that will provide ongoing support. We maintain a pool of excellent resources that excel in maintenance projects but don't have the capacity or interest to be architects.
http://jacquesmattheij.com/The+Starter+the+Architect+the+Deb... was pointed out to me as another recent and good article on the same subject.
Finally, I assure you that successful Starters are excellent networkers and communicators. They have to be, or else the project will never leave the gates.
I'm a starter, but I know about finishing and I think it's a good skill to learn.
In both scenarios you see the same pattern: once things get off the ground, the co-dependency relaxes because the starter can always hire finishers, but not vice versa. Look at who you hear more about: Jobs or Woz? Gates or Allen? There's definitely a difference in their levels of success, and definitely in their personalities. (Not saying it's the only factors, but certainly important.)
The more accurate way to put this is "I am not a Finisher". The argument here is that starting and finishing are two equally valuable skills that are somehow equivalent.
A "Starter" is a fairweather friend. It's easy to start things. Most people like starting things. Note this is different from networking and so forth, which is really a separate skill altogether.
Employers, business partners and investors will look at what you've finished and don't care what you've started. When something is 80% done or when times are tough or it's time to soldier on and run the last mile of the marathon, nobody wants the guy around who says "well, I started, that's my skill but I'm done now, I suggest you find a Finisher".
Not being a Finisher isn't a different skill--it's a character flaw.