Your first sentence doesn't seem to me to match the rest. It seems like much stronger advice, objecting to many more founders. The rest is about not committing to one project too early, while the first sounds like a much stronger advice against not being an entrepreneur for the sake of being an entrepreneur. Steve Jobs wanted to be an entrepreneur and tried a lot of things. Similarly, I think Zuckerberg wanted to be an entrepreneur, but it's harder to tell because his first commercial project was successful.
Also, some people complain that the "infinite runway" makes people fail to give up on bad projects. And, worse, to concentrate on the parts that interest them, rather than tackling a full product with sales and marketing.
Entrepreneurial ideas come and go. Some I don't give a second thought to. Others I commence market research for, examine the competitive landscape and explore the feasibility for development. This can be time consuming, and has yet to have produced any tangible, commercialized product.
I figure it's about time I devote the time I would spend to exploiting my existing repertoire of knowledge to develop an idea, to exploring parsimonious, efficient techniques for assessing viability.
In my search I found [Autopsy.io], a startup graveyard. Founders describe why their startups failed, concisely. It made me think about my past startup ideas and why they haven't flied.
I'm going to work that out, put it in a spreadsheet and regress to whatever problem keeps popping up - then, I'll work on improving my subject matter knowledge in that domain - for example, if its the feasibility of implementing with existing technology - I might learn more about the current technological landscape in general. Or, more about existing services for investors, if my product is a service for investors, like my last startup idea, which I have autopsied in detail here
I just thought I'd share my general strategy for anyone who'd want to copy this procedure for startup autopsy. Please use this space to suggest other appropriate diagnostic methods.