I both agree and disagree.
I agree with the point you are making, but at the same time you seem to be countering a point that doesn't seem to be exactly the one being made (at least from what I have really seen).
When I see people complain about games being restricted I don't see them meaning in the sense that they will have less creativity. They tend to mean that they will have less creative freedom. That by caving into people saying "This is bad" or "You shouldn't be doing that" they are paving the way for people to dictate what developers can and cannot do. That would be stopping developers from making the games that they want to make and they will end up only making games that the loudest people want made, so as not to get any backlash from it.
I suppose the Mass Effect 3 ending is a good example. They chose to make the ending as it was originally and people complained about it extremely vocally. So they released the extended cut. Many people argued that by caving into the people complaining the developers gave up their creativity, because they didn't make the ending that they thought the game should have, they gave in and created the ending that the complainers wanted.
I think the fear is that if enough people start complaining about certain features in games, it will become considered socially unacceptable to have those features at all. In some ways that is actually a valid point. If people complain non-stop about sexy female characters, then eventually they are going to stop being made at all, because developers don't want the constant outrage over it from tarnishing the games reputation and giving it negative press.
It is a similar point to the one you made last week in fact. Developers don't want their fans ruining their success by harping on at a single negative review, and likewise I sincerely doubt that the creators of something like Dragons Crown wanted people only going on about the female character designs. They put a lot more into the game than titillation (I am assuming here, I haven't played the game nor do I particularly want to) so by people only dragging down the discussions to complain about the boobs, they might be put off creating such designs in the future.
People often say they don't wish to stop these kinds of things being made, only to have more choices and variety when it comes to games. A much better way of doing this is to praise the ones you like, rather than rant and rave at the ones that you don't. If people who like buxom characters praise them, games will have them. Likewise if people prefer their female characters more reasonably proportioned, then they should be discussing them and praising developers when they do make them. This will encourage them to make more.
Which doesn't happen very often to be honest. Even when developers do make decent characters to appeal to a wider audience they still get complaints. Tomb Raider, Bioshock Infinite and The Last of Us all got sexism complaints based around how they created their female characters, and how is that going to encourage more variety? It's just going to put people off and in many ways that does dampen creativity.
Holy Hell that post was a lot longer than I originally intended.