I don’t, actually. I just hate the HoN community more than I hate the LoL community.
I mean, there are some things that LoL does better, but there are also things that HoN does better. Summoner spells are cool, but Flash is too good to not take, which makes it a little pointless. TPs versus free recall, the sustainability of the healers with massive mana pools and high mana regen, the lack of denies, all combine to make League of Legends even more of snorefest in lane in comparison to HoN’s, but the presence of a good jungler can reverse that and make it actually interesting.
The UI is a series of tossups too; League of Legends shop is less laggy, HoN’s is more usable. LoL’s portraits are nice, but they lack HoN’s ability indicators. It’s nice to be able to tab and see your enemies’ items, but it’d be nice to have HoN’s quick-view thing on the upper right. HoN’s pathing is better, but brush is saner than the tree-jukes. Wards are more powerful in HoN when placed well, but they get placed in larger numbers in League. Tower aggro and creep aggro feel saner in League of Legends, but the big shiny line that is tower aggro is a bit hand-holdy.
I could go on, but what’s the point… I think HoN is a more fun, better game, but the combination of S2 giving up on balance in favor of just more shitty skins (and the rest of their business decisions) and the worse community of HoN (plus more Qt3ers who play LoL) means that I’m going to drop HoN entirely and get better at League.
(Edit) Also, Heroes of Newerth has a vastly superior item selection and a huge variety of heroes with more interesting and powerful skills than League of Legend’s champions. Everything is more deadly; stuns do more damage, have wider AoEs, longer range, and faster projectile speeds, for example.
Take Hammerstorm (a HoN hero) as an example. In HoN, he’s a mediocre hero because of being a melee semicarry. However, his skillset would make him one of the best champs in League of Legends, with a stun second only to Amumu’s ultimate. Flint Beastwood is Caitlyn’s closest equivalent - they’re both ranged AD carries with an equivalent ultimate - but instead of her skills he has a massive sight-granting persistent snare-nuke which does huge damage against towers, a passive which, when levels, grants him higher attack range than a hero’s daytime sight range, and a passive which, when leveled, grants him a chance to proc a stun on his autoattacks, which stacks with Savage Mace.
It’s not just heroes who are more capable and more lethal. Items are more powerful as well, and there are far more of them.