New Yorkers on the subway...in rush hour

Does anyone else wonder why New Yorkers just loooove to crowd themselves at the door of the subway cars? I mean, if there's no space in the isles of the train cars, I get it. But you see lots of people don't even get the chance to get on because people don't want to walk 2 more steps into the isles. Well, whenever I see that going on, I squeeze myself in anyway, because I have places to get to and no time to waste. Life is too short for that.

ps: don't get me started on the "train standers". aka people who like to stand and wobble through the whole journey when there are several seats available. I just don't get that.