Sorry to hear you had trouble getting in but the door policies is what makes Berlin clubs so special. They filter out the people who simply do not fit in the vibe and atmospbere that they are trying to create. The whole thing goes much deeper than simply dancing to music with your hands in the air. Once you inside it is combination of the venue, music and the crowd which creates this insane surreal feeling where you think you are in a movie...some kind of different dimension.
The key is to not take it personally and simply move onto the next venue, there are so many options that you will get in somewhere eventually. Gotta do your research tho, know what party you are attending, what djs are playing, what type of crowd it brings. For me it makes the clubbing more exciting, it becomes an adventure