Honor doesn't really need to be renamed just because it seems like more people honor carries rather than honorable players. The whole point of the Honor Ceremony in the post-game is to allow players to vote on who they felt had the most positive impact on their game, and if that means the carry...Well, so be it, that person can honor the carry.
Especially since the Honors (GG <3 especially) are very rough, general categories.
And besides, that's just in regards to the Honor Ceremony. The rest of the system is holistically geared towards recognizing sportsmanlike behavior.