And how, exactly, is she supposed to put her knees in any other position? The seats are not very wide. Unless she has an empty seat next to her (and, frankly, that's about the only way I can stand to fly any more), if she tries to bend her legs so that her knees aren't right in front of her, parts of them are going to be spilling over into and annoying the person next to her, or sticking out into the aisle and getting run over by the carts that the flight attendants drive trhough trying to get people to buy stupid duty free stuff.
The problem is not inconsiderate assholes. The problem is that 6'2" people are stuck in plane seats that they simply don't fit in. The problem is that airlines have designed coach seats to work for the bottom 30% of the population in terms of size, and are trying to squeeze the entire population into it. Something somewhere's gotta give. The person in back can blame the person in front for reclining their seat (as we've seen in this thread), or the person in front can blame the person in back for having knees (as we've seen in this thread), but *somebody* is going to be unhappy, because the situation is set up so that somebody has to be.
The problem is coach seating. It's just become too small.