Inclusion of Characters in Movies and Series: What's Not Right

In previous opportunity I had commented on what I thought was good about some characters and communities that are now more taken into account in audiovisual productions, this time I will do the opposite: I will mention some negative points of this subject. Remembering that yes, what is expressed here is entirely my opinion. If you have not read the first part, at the end of the post I'll leave you a direct link.

1) Flat characters: "Hi, I belong to some LGBTI group and I'm only here because of that". Basically they are characters that have no argument, no reason to be in production; They are easily detectable because, if you could eliminate them, you would not notice the difference. If flat characters are bad, think of when they do it only by forced inclusion. Do you know any character like this?

2) And what happened at that time? At some point the characters adapted to the tastes of someone or trends of the moment; This can happen at any time without taking into account that the work has been completed. It is important to clarify: the previous thing occurred without having given indications of it. Albus Dumbledore was one of the most famous cases.