Yeah if it's their full-time thing then it's a more reasonable expectation for them to be working on the games as much as possible, within reason like you said.
That's usually not the case, often having regular jobs on top of other "real life" stuff going on AND sometimes being a solo project as well.
Not like there's 15-20 people working 30-40 hours a week on this game.
I don't think it's realistic to expect most of the devs of adult games to have any kind of a team unless they already have a very successful game under their belt earning enough money to justify it. If you're Dr Pink Cake (Being a DIK dev), sure you could certainly afford a full team. But most devs have nowhere near that level of support. How hard would you be willing to work for someone who could only afford to pay you $100 a month?
In fact most devs have a full time day job and are doing their little indie game as a solo side project. So even expecting 1 person to work 40 hours a week on it is not very realistic unless they have enough support to be able to quit their job and work on their game full time.
Now for the devs who actually HAVE quit their day jobs and are just doing their game development as their only income source, you would think they'd be strongly motivated to put their nose to the grindstone. Their paycheck is entirely dependent on the quantity and quality of their work. So yeah they could coast along and not do much, but that's going to be obvious to their fans pretty quickly.
I will say that I think most devs do their initial release too early. I think they'd get a better reception if their initial version was solid enough for people in their target audience to really be wowed by it. You want that first impression to really be a good one. After that there's kind of a happy medium you want as far as dev cycles. You want to do a release often enough to keep people interested but you want to have enough development time during each cycle to actually make significant progress. People will tolerate a long dev cycle if you have a track record of delivering a huge amount of content when the next update comes out. They won't if it takes you 6 months for an update that has hardly any content.
Being a DIK is actually a great example of a game with a really long dev cycle, but when that update does drop everyone knows it's going to be huge and it's going to be impressive.
