Henry V’s rhetoric

What I find most interesting about Henry V is that I can see a clear difference in his language compared to some of the other characters in the play. He never uses malaprop, unlike many other characters, and he is so well spoken, that it is almost like his rhetoric is his greatest weapon. He can inspire a crowd, strike fear in his enemies, and can persuade anyone around him. His dedication and seriousness to his throne also helps give him a very heroic quality, making Henry V a very likable character. What I dont understand is why Shakespeare has this tendency to kill off the main characters in his play. Personally, it really detaches myself from the play whenever a main character dies. Why do Nym and Bardolph die, but Pistol lives? Shakespeare made Henry this merciless leader who, while being an excellent king and protagonist, is heartless when it comes to his friends. Much of modern day stories, novels, and plays focus on the value of friendship and how it trumps everything else, so when we see Henry order Nym and Bardolph to be hanged, it seems very un heroic/protagonist-like of him. In the end though, Henry’s other characteristics still make him a protagonist of quality and someone to be liked, despite the unnecessary deaths of his friends/other main characters.