Trust me I know, I have surprised alot of people with what lanes I can beat as Morde. However he still looses to anything he cant hit back which is alot of champions in dominion. While morde is a nice counterpick due to the utility his ghost can potentially provide that doesn't mean he himself is better than other champions, he is highly situational and should be treated as a dedicated counterpick. Thats why I feel his placement is too high, situational champions should be midtier at most.
But, I didn't bring the "pick him against carries" thing up because carry ghosts are so strong. I brought it up because most carries have to build offense to do damage, and only one or two mpen items will have you doing true damage to them whenever they go to trade. I laugh when I go against a Graves or an Ezreal as Morde because I know that a simple Warden's will let me totally zone them out. Its the champions with LOTS of range that truly counter Morde, like Cait/Kog/Cass/Karthus.
Against most midrange champions he will be able to trade pretty well with E and by Q'ing onto nearby minions, and his item builds are also fairly efficient goldwise which exemplifies his expected midgame strength. Then there's also the way his Q scales into the lategame: this ability is often very overlooked, underrated, and sometimes not understood. Morde can end up soloing Jax in long games because of it, which can singlehandedly win a close match for his team.
I've played him a lot and I feel Morde deserves his position as the front of tier 2. He has counters, but with smarter play they're not as numerous as I originally thought. He has a weak earlygame but can focus quickly on mpen and one defense type to get the ball rolling. Overall, his strengths outshine these weaknesses by a long shot.
So yeah, that's my reasoning on him.