For example, you say that you don't know how you'd convince 13 year old girls to be interested in programming. The normal interpretation is, 'Clearly 13 year old girls are very rarely interested in programming, and Paul Graham doesn't know how to change that.' The nasty interpretation is 'Paul Graham thinks that girls are intrinsically incapable of being interested in programming'.
It's easy to be offended by things. It's also obnoxious and often irresponsible.