I think the more salient question is: why do you care what other people are doing on their own time? Personally I don't like sour cream, but I don't get angry if a stranger orders a burrito with it.
Because it makes me feel useless when I code. It makes programming seem pointless. It makes me feel as if I've wasted the last 3 years of my life learning to program.
I think it's pretty obvious you're just starting out with programming, as all of your comments show.
And no, you didn't code anything from scratch in Java. Java is a product someone else coded for you so you could save some time, just like a game maker. The fact that you don't understand this after 20 or so replies at least shows me that you've got no clue about what you're doing.