"More solo carrying" is the issue, not the solution!
Lately I see a lot of posts on the boards regarding the current game state: People feel that a single bad team member can lose them the game, while they themselves can't carry. Either I'm stupid, but I get the feeling a lot of people here on the boards don't understand how the game works, and what the actual issue is. What people are complaining about and what they want are one and the same.
If you have a feeding midlaner that goes 0/6, that means the enemy midlaner is 6/0 (not accounting for kill distribution from ganks). This midlaner can then roam to other lanes, kill the players there and snowball the game. This midlaner is thus solo-carrying. If a player is losing you the game, that means the equivalent on the opponents' side is solo-carrying the game. You can be 3/0 in toplane, but you're still not as good as the enemy midlaner. Adding more solo-carrying potential will thus benefit the enemy midlaner more than you as a toplaner. As a result, the effects of having a bad midlaner on your team only become stronger and stronger.
The real problem is that there is no incentive to help out a losing lane. Therefore the game feels like you're playing as 5 individuals instead of as a team. As a result, a single bad player can lose you the game. Currently the risk of helping out a losing lane far outweighs the benefit. You will likely lose a large chunk of your turret's hp, miss out on farm, and there's no guarantee you can get off a successful gank. The promised increases in shutdown gold should help here, since the reward for risking a roam will go up. Of course more has to be done, but that does not include solo-carrying/snowballing. Good players should influence the game by helping out the weaker links on their team, not by one-shotting everyone.
Additionally each role should have an equal impact on the game, which is currently not the case. Lanes should be balanced so that one lane/role does not hold too much power compared to others. Otherwise it can feel like you aren't able to influence the game, when you play one of the weaker roles.
Edit: Since a lot of people are complaining this issue isn't solely related to laning phase, I agree. That said, it still does occur during laning phase, and some of the posts I refered to were specifically complaining about the laning phase. I have seen plenty of games myself in which a single opponent gets 6 kills by 10 minutes, then proceeds to solo-carry the game. This issue is much easier to resolve than fixing the issue of having a bad team member in the late game.