Update: After selling out on Toranoana, it has also sold out on Melonbooks now. Wow, never saw a H-game sell out so fast after release before.
What you say is also not entirely true. Anime doesn't technically fall under the pornography category and is considered as "art" instead. Same reason you're allowed to upload stuff like hentai scenes on Youtube. The big alert factor is when characters appear on the cover which look like minors (below 18 years old). Same reason that's not allowed to be uploaded on Youtube. Pretty sure you'll be just fine importing this game for example, containing only beautiful busty women who are clearly looking like they're older than 18.
Even if your country somehow has a special law against this, it'd be an exception to the above rule which makes it a minority, so it's not a good counter argument. The fact is also that a majority of the people who pirate are leechers who could easily afford to support a few specific artists / games they really like; they just don't because "free st00f pl0x". And many good things in life have ceased to exist because of that, including all H-game brands who were devoting budget towards animating as much as possible to make the H-scenes look great, for example: G.J.? , MBS Truth, Ole M. Atelier Kaguya survived only because of how big and popular they are in Japan.
There needs to be a large scale realization that the only thing which is holding the H-game market back from becoming great / progressive = people saving money on literally anything you can save money on. That money is now going towards gacha / mobile games instead, which allows said developers to milk the consumers instead (mainly their wallet, lol). For example, I spoke with a person who spent $5k on Kamihime Project trying to get a girl he wanted and didn't get her. It's no wonder that companies such as Lilith went this route. Don't be surprised to see more games like Project QT in the future either.