This is a pretty selfish mindset to have. If someone shares a fan game, it's probably for one of two reasons: either the developer needs assistance from people with different skill sets (as few people, if any, are excellent programmers, artists, writers, designers, and musicians wrapped in one) or the purpose of the project is as a means of getting involved in the community (i.e. developing the game in broad daylight and discussing how original ideas can be built upon and improved as you go is a fun way of connecting with a group/community/hobby that you're part of). For many people, making a fan game or mod is no different from making art or animations, or composing related music, or baking cakes shaped like characters, or doing something with whatever talents you have; it's to be part of the community and to express yourself.

To chastise people who share their projects because they often get shut down is to say that all you care about is whether you get to play the game (for free no less), with no regard for the people actually spending thousands of hours making these things. Why don't you try making a fan game without soliciting help or enjoying the years-long process by sharing it with people in the community.