For the most part, yes, that is the reason cause the majority of the complainers are angry there isn't any sexual content to the extent they want to see. Very few are making any logical, valid or relevant complaints in regards to the story or themes. It's all been about the lack of sophia getting it on. That should be telling you something. Case in point in below poster's comment. Go back through the thread and you'll find this is the basis of 2/3s of all the complaints being made, that and duration between updates.
The dev is sticking to a plan, a plan that doesn't meet the personal expectations of some. That's the problem with holding expectations about anything, it'll only ever lead to disappointment. Why some people are complaining that this dev isn't more like DPC and turning out the same content is just plain ignorant. I've seen so many make that argument in this thread that it's become absurd, laughable and downright inane.