Suggested Item: Relic Shield for Thresh on Summoner's Rift makes no sense

I don't understand why Riot recommends Relic Shield for Thresh on Summoner's Rift. He attacks as a ranged champion, so he can only produce the heal/gold share if he gets a real last hit on the creep. If he doesn't get a real last hit he affects the lane partner's last hit timing and neither of them get the gold or the heal. Its a total troll item choice for this champ. Thresh performs much better as a support with the Ancient Coin which can still be built into wards if the player wants health or it can be built into the speed item if the player wants armor. Ancient coin is far superior for this champion and I find myself arguing with a lot of noobs about how relic shield makes no sense for Thresh. I'm a level 7 mastery Thresh and I've played him in all positions with all different kinds of builds. We can argue all day long about a lot of stuff but I'm sure we can agree that Relic Shield is pointless on Thresh.