The Randomness wrote...
Relax, it's all done for entertainment. How I see it, NTR/bad endings have the "best" in terms of animation, variety and expressions. It's also an alternative to porn with it's vanilla stories everywhere.
Ahegao, which is the orgasm face is very easy to get a reaction/turn on from if done right. NTR manga by Alice no Takarabako are a good example of ahegao by NTR.
That's why NTR/"bad endings" is fun to look at, the sex and expressions are easy to masturbate to.
Pretty much going to side with Random on this (btw Ran-Ran been far too long, hope you're doing well)
Entertainment and fantasy scenario's on extreme subjects for the sake of eliciting different emotion's is the overall reason for bad ending hentai works.
Sometimes they leave me with an empty feeling or in some senses a sad feeling (or maybe disgust is better?). Anyways, I don't dislike it when I feel that way, rather I give the artist credit for coming up with an intersting (usually twisted) plot and enjoy good artwork (and voice acting for animated works). Probably will take a break after I get my fill, watch/read some lighthearted stuff and then go back to the darkside later.
Just a matter of preference when it comes to certain genre's so you either go with it or read/watch whatever your into and avoid what you don't like.