Earlier quoted context omitted.
If you give up too quickly, and don't focus and create too many applciations?
Come on, he's only 17. Why do he needs to focus? He was just doing this for fun. As he grow, he'll have more the sense of business and the will to make money/create a company and will focus on one product. Nevertheless, this will give him varied experience that will improve his choice and selection later.
Written by 14 year olds. Several orders of magnitude more difficult than what mark has done. (A lot of asm, 3d code, matrix maths, fitting together pascal, c, asm in DOS, etc)