Riot claims to have as their first concern differentiating between a bad game and an intentional feeder, so at least they demonstrate an awareness of the complexity of the issue they are addressing.
The problem is that often the two issues are connected. You stop caring as much about dying if you're having a bad game, and so behavior gradually shifts closer and closer to intentional feeding. I very rarely see blatant intentional feeding; it is much more common to see someone behaving purposefully stupidly due to frustration.
I'm also concerned about how this might impact legitimate strategies, such as proxy Singed. Will people be afraid to try to steal baron if they're having a poor game as jungler because the death and risk of being labeled 'intentional feeder' outweigh the obvious strategical reward of stealing the baron?
Lots of problems have to be addressed to make this workable, and in general unless someone says 'k I'm feeding' then they shouldn't get banned for intentionally feeding.