RGIII - partially torn ACL

first, let me say - i'm a diehard seahawks fan, so having a gimped out RG3 in the game was only helping my boys. that out in the open, i say the following as a diehard football fan:

how the f*ck can anyone justify leaving RG3 in the game on an OBVIOUSLY gimpy leg?  MAYBE if they had a shite backup, but Kirk Cousins is a more than adequate backup, you might even make the case for him as a decent starting qb.  RG3's the goddamn franchise man, you don't f*ck with the future of the franchise.  WTF man????