Japan's population has been suffering a decline because men and women are lacking desire to be connected in any meaningful way. Partly to blame are historically strict gender role enforcements which, largely, has been pushed back on, and let's face it, resulted in an overwhelming amount of grown men rejecting the notion they should go out and have a career and instead spend their days withdrawn into video games and anime/manga. Likewise women have become more career-driven when they've been told culturally they should stay home and raise a family.
Couple that with the way Japan has mastered commodities and you've got a recipe for people to live in completely self-serving bubbles. Give that a few years to ruminate and become commonplace and now we're talking about anime studios being compromised of obsessive anime fans who have never learned how to interact with women. This is, in fact, according to Hayao Miyazaki, who asserts this is the reason the quality of anime is dropping so drastically. The men who have written these perverted characters think it's funny because they have never been in the real world where that kind of behaviour is completely unacceptable and isn't even humourous. The more these perverted characters have a presence in anime, the more skewed their perspective becomes. The issue continues to perpetuate itself.
Personally, much as I try not to let it deter me from watching an anime, it really has ruined a ton for me. 7DS is a perfect example of an anime I find entirely unwatchable because, fundamentally, you cannot have a character with any depth nor meaning when their whole personality is based on a trope born from a sheltered and detached life. The issue is made far worse when that character is in fact the MC, as is the case with Meliodas, who as a result is shallow, fake, and gives me no reason to be interested in whatever struggles he might presumably face, which in turn makes the entire anime a wasted potential.
And, sadly, as others have already pointed out, it still makes money.