That's a valid perspective, and one that can help you become a world-class specialist. Entrepreneurship, however, very much requires you to be a generalist. There are just too many areas to consider: fundraising, hacking, product design, user acquisition, recruiting, leading a team, product management, marketing, PR, accounting... Zero entrepreneurs are well trained in every one of these areas before doing a startup. Entrepreneurship is about trying to learn how to do something new, unfamiliar, and unpleasant every day. This requires focusing on your weaknesses, even in areas you aren't inherently passionate about.
You certainly don't have to be a generalist to be successful - world-class specialists add much more value to the world than the median entrepreneur. But you do have to be a generalist to be a successful entrepreneur, and it's in that context of entrepreneurship that you should evaluate Jason's post and PG's essay on resourcefulness.
But you do have to be a generalist to be a successful entrepreneur
I don't believe it.
You may have to be willing to dabble in these areas in order to get started, but if your strengths are technical, your goal is to do them only until you can justify paying someone else to do them. The entrepreneur who tries to manage every angle of business will never grow beyond his personal limitations (time being the big one).
Again, it's about opportunity cost. Pay an accountant to do your taxes if it's taking you away from money-making work that you're actually good at.
You certainly don't have to be a generalist to be successful - world-class specialists add much more value to the world than the median entrepreneur. But you do have to be a generalist to be a successful entrepreneur, and it's in that context of entrepreneurship that you should evaluate Jason's post and PG's essay on resourcefulness.