Also it doesn't explain the correlation with the recession.
What followed was what I observed from my personal experiences, and I did not say that my personal experiences necessary reflect the state of the whole of Japan, nor vice versa, or prove this article false. These are just my personal observations, which happen to be the opposite of what was stated in the article.
Also, in addition to the very small sample set (3000 out of millions, even if we are just considering the age group mentioned), it also provides little to no detail of the sample selected (location, marital status etc). IMHO this is article seems sensationalist to me, or just bad journalism (no links to concrete sources or data).
Also, I have lived in Japan for the past 5 years and around me at least a lot of people are (very) sexually active, in fact, too active, or too casual usually. Most guys date multiple girls/have multiple sex friends, and even if they're married or in a relationship, many have sex partners other than their girlfriend/spouse.
Despite the misleading title, I wouldn't be surprised if couples reply that they haven't have sex with each other for the past month and were telling the truth (because they're too busy having sex with other partners).
Still, I honestly don’t understand why this is the hill people want to die on, what they feel most betrayed about. Like I haven’t seen some people this upset since Firefly was canceled.