Looking closely, there is 2 more commonalities between the 4 games.
1.) Enemy top Lane is never out of the game. Despite your KDA, they are always never far gold wise with some of them having higher gold then you by the end. Plus, with the exception of Darius, They had kits that were useful in teamfights regardless of how much of a gold deficit they had.
2.) The Enemy jungler is really big, either getting a ton of assists or in the last one's case, kills. Very likely, the jungler camped bot placing extra effort in shutting down your adc. Likewise, your junglers, with the exception of amumu, had no real beneficial presence. Jarven and Gragas had very small KDAs meaning they either farmed only or did a ton off ganks that accomplished nothing. Twitch fed in his game. In all the games, you only at most had 1 dragon and even then only half of them did.
I'd put the blame squarely on the jungler. In all games, the enemy jungler put tons of pressure on bot in an effort to control dragon. What your jungler should have done is counter camp top to quickly take your tower and free you up to roam. Shutting down their top laner as well. Instead your junglers either farmed, ganked poorly, or tried in vain to get bot under control. In all cases, contributing effectively nothing until the late game, where only Amumu had the cc and engage to do something useful, but by then it was too late.