52 paintings in a year was not uncommon for painters that are now revered as old masters.
Good ideas and inspiration are, despite your opinion, largely a product of routine.
The routine of capturing thoughts and directions followed by the routine of planning, implementation and possibly review.
The idea of a tortured artist throwing a smattering of paint at a canvas in frustration because his "spark" is gone is largely a figment of the modern imagination.
Art has been made to order on demand for most of history.
EDIT TO ADD: Downvoting without a response? Thanks for proving my point.
It is a fine method of developing one's art/science/etc... skills to regularly practise, but not a fine method when it comes to startups and founding companies, think I; for such things happen to have consumers, people who may be favouring the product and incorporating it to their daily lives, which will be disrupted when the founder loses their interest in that product and proceeds to the next month's startup.
They may have had a goal of building 12 web sites in 12 months, or 12 blog posts in 12 days, but this person chose to launch 12 startups each month, and launch those to press. Launching companies regularly is dissimilar to painting regularly. (TBH, I did not double check if this serial founder is referring to some ordinary web application as startup)
Well, according to http://www.paulgraham.com/startupideas.html you can literally go and find good ideas right now and every day thereafter.
It is also the basis of the Lean Startup Machine weekend (phenomenally popular).
You can train yourself to have ideas. Good is just an evaluation system.
People may indeed be incorporating a new product into their lives and the Founder will need to manage customer expectations and fallout. A high likelihood of discontinuance does not disqualify his attempts from being a startup.
The truth is, from a validation perspective the OP may have stumbled onto a supremely successful model of idea validation. Build it, tweak it, pump it for 11 months. The next project has 10 months. The next 9. Etc. Compare the metrics after one year and choose the most successful.
However, the statement that good ideas do not come up routinely and is false. They may just not be routine for you
inspiration: A sudden brilliant or timely idea 
If an entrepreneur trains via founding companies, then, should an architect train via filling the city up with half-arsed buildings? Nowhere in the pg article does occur something like “build random ideas into companies routinely”. Also, in that write-up is writ:
> If you're not at the leading edge of some rapidly changing field, you can get to one. For example, anyone reasonably smart can probably get to an edge of programming (e.g. building mobile apps) in a year. Since a successful startup will consume at least 3-5 years of your life, a year's preparation would be a reasonable investment. Especially if you're also looking for a cofounder.