You're making it sound like you need to be a professional writer to earn $10/month. I can earn that amount with maybe 20 minutes of work every 2 or 3 days, which, by the way, anyone can unless they're computer illiterate.
Whether you're better off washing cars is another argument.
Whenever I see people giving these estimates about how their blog is earning $5 a day without doing anything, they always seem to be low-balling the amount of time they spent on it.
I've had multiple ad sense websites and they all net below $1/hour. I'm sure I can improve that, but not enough to be a worthwhile part-time job.
I would be happy to have someone prove me wrong by helping me build a low effort $10+/hour blog, but until then, I remain skeptical.
So writing something for 20 minutes every 3 days (which some might even enjoy) counts as a part-time job? It's like saying browsing on HN is a part-time job. Or were you talking about the $5 a day? In that case, yes, you might have to put a little more effort into it.
However, building a blog that earns $5 a day without doing anything(or let's just say, doing a lot less than you're supposed to) is possible, but it's just not ethical.
Let's not get hung up on definitions here. It doesn't really matter if $10/month is a job or just a hobby to you. The important question, is whether or not it is attainable with low effort as you seem to suggest.
I've built a few websites with pagerank 2-4 where I spent more than 20 minutes every 3 days and enjoyed it. All of them have netted less than $10/month over a span of 5 years.
This experience has led me believe it is not possible to even get to $10/month without treating it as a job...unless you happen to enjoy blogging about acai berry and prescription drugs.
Whether you're better off washing cars is another argument.