Me too. Experience, opportunity, events, etc should change every character as a story progresses. In fact, you could argue that the story itself cannot progress unless the characters change. Events happen in a story, but they're merely plot devices, catalysts. It's how those events change and influence the characters that is the heart of the tale.
But I also get that there are other people who believe that every character should stay static unless the player explicitly makes them change by making a choice. They want total, absolute control. Put another way, they want to BE THE story, not merely a character IN A story.
Here we partly agree and disagree actually. Yes a character should have a basic personality and way he/she perceives live in a game, their own motivation for things that happen and yes that character should change and grow based upon what happens in game, but the way that character reacts to certain things while that happens is canon for how that person reacts to those things.
That is exactly what destroyed Sunny, since she is now shown she will be easily seduced by any player coming along and can be turned into his mindless sex toy if MC forgets to give her some attention or does not save her from that hellish fate. Now that makes her a bad LI. Now instead of her being a sex addict (I might put it strongly to put my point accross
), you would have found out she had or could easily get a gambling addiction unless you watch her 24/7 and was quite likely to rack up ten of thousands of gambling debts while living with her putting both of you into debt. Would you still think she was great wifey material or to big of a risk?
Well that is the thing, for those who see the character as the same on both paths, you know how she will react now unless you watch her like a hawk and interfere all the time and you better not ever have a job that makes you have to spend two weeks away from her.
Edit: What goes for Sunny goes in a way for every girl that already fell and were made into their toys by Marcus or Weiku in the NTR path, just Sunny grates even more since for a lot of players she was one of the two main prizes to go for in the game. The problem is there as well though for the other women in game before MC even could connect with them. Basically there are not that many romantic interests left for those who see them as same character on both paths, just fuck interests.
It is not for nothing that combining NTR paths and romantic paths in one game is one of the hardest things to pull off and keep all intended players happy, since the needs and wants of the one are kind of opposite of the other and it is very hard to write believable ways for a woman to fall into the NTR trap and have her enjoy that and still be believable as future wive material. (Except maybe for magic, mind control and rape that the female chars hate, which have their own problems with believable or subject matter). I am pretty sure I could not do it if I tried.