I agree with you that work is what you do to get paid. Hobbies are things you enjoy doing and may work at, but they aren't your profession unless they're helping you pay your bills. That said, even if you don't care about making money off you blog (or other hobby) it's good to monetize it at least a little so that you can write part of your expenses off on your taxes.
I personally wish I has more readers on my blog, but not enough to devote more time and effort to it. I also know that nothing kills the love of a hobby like turning it into a second career.