Why does Tahm Kench have higher-than-average melee range?

Him and Morde are the 2 highest melee ranged champs in the game(minus upgraded AA's such as Wukong's Crushing Blow or Aatrox's ultimate), yet he also has an AA buff that scales with tankiness, and after landing 2 AA's and a Q(which is relatively easy to do, especially with the increased range), can eat an enemy dealing 32% max HP and removing them from the fight for 2 seconds(which can easily determine the tide, such as eating a tank meant to protect their ADC like Alistar or Braum and leaving them exposed), and a slow, or situational stun again that only takes 3 AA's(or 2 AA's, a Q, then wait for the Q CD which the passive won't wear off by that time).

Its like, I don't even care if he has all that stuff... well, yeah I do but I'm not gonna complain. But a big problem is that along with it, his passive upgrades most of his stuff and his passive is easily stacked by his high AA range. You just Q them, walk up, AA them twice and even if the slow wears off when you get there you'll have enough range to hit it twice and then eat them.