Concurrently renting out 2 rooms so often that you would want this, is still a qualitative difference between renting out just 1 room or renting out your whole personal residence for just 5 weeks in the year. I don't know that it crosses a meaningful line yet, but it is moving toward the "professional/large-scale" side of the spectrum that your parent comment is complaining about.
Disagree to an extent. If you have two extra bedrooms in your house besides your bedroom, you should be able to have 2 listings.
The rule should be "only N listings that belong to 1 property".