Attack on Titan: Shingeki no Kyojin

[DarthEnderX]

Killing the god parasite wouldn't really help, because you don't know how many more exist. For all we know, the world could be filled with those, just waiting to make contact.

So? They've found one in the last several thousand years. If it would solve the current problem, it's not worth doing cause maybe the problem could come back in a few millennia?

"There's no point curing this disease, cause there's probably just gonna be another disease someday!" is a really weird attitude.

My guess is that you can only exhert control over the titans made from your essense/dna/whatever. The mindless titans here were made from Zeke's spinal fluid wine, so I suspect only he can direct them, and he's nowhere to be seen right now.

But Eren is directing the wall titans. And he didn't make those.