User blog comment:TheTobarMethod/HP Stacking, This Is An Issue/@comment-74.73.27.88-20130216004616

Health stacking is only popular because riot made it ridiculously easy to shred armor. There are so  amny items with armor pent and black cleaver is argueably the most popular item for brusiers right now which makes stacking armor inefficient but stacking health a lot more rewarding.

Health stacking is a huge problem because it made some characters weak and others a lot stronger. Olaf for example can just stack warmogs and sunfires, live for a long time and dish out dmg with his E but Irelia whose dmg comes mostly from hiten style is suffering because 75 true dmg per hit isnt much when the enemies have 4k hp