The problem is not my or your ability to deal with the issue, the problem is the existence of it. Therefore any "solutions to carrying" is ultimately bogus (because if it can happen, it will happen). It should not exist and wouldn't exist if "raiding" in AoC was designed better overall.
T1 and T2 is how everyone starts and they drill into a new player the idea of being an irresponsible, unresponsive and unimportant slot filler who gets carried is the norm. Then suddenly Miasma/Blood Draw means he/she is dragging everyone down because he/she's useless dead weight. At that point he/she either sucks it up and improves or figures being insulted by random internet *******s over some stupid game isn't worth it.
There's a massively gigantic disconnect between first two tiers and the higher tiers. This corresponds to the shift in AoC's general direction that happened after 1.5, it started to become more of a PvEr's game and this is very clearly seen in raids. Remember this? Raids left from old balanced (or even PvP centric) game are casual, social event type of things including the original design of T3, while newer tiers made after game shifted direction are hardcore PvE content starting with actual T3. And this jarring shift very badly screws over casuals, followed by more trouble for everyone.
So what's the solution? I see two ways out of it. You either have 2 difficulties starting from T3: Normal modes would be for those casual players who want to drink beer and chat with buddies on ventrilo, with everything nerfed to T2 level. Unchained modes (we all know it'd be named unchained) would be made even harder, restoring T3's difficulty back to its launch state and going on from there.
Or you revamp T2 so it's more in line with PvE focus of the game, something that contains very much easier but recognizable versions of Miasma/Blood Draw, Thoth puzzle, Archfiend/Zodiac positioning, HK/Sheng/Emperor style of kiting etc to make certain nobody can get away with slacking and everyone actually learns to be a PvEr. This could completely shut off casual players from raiding, which seems a big downside, but those players already don't bother with high tiers anyway.
Or FC could just go on ignoring it. That seems like the most likely outcome.