OP is right.
Itachi´s Tsukuyomi = 1 sec in real life equals 72hours for the victim.
Lets take Naruto for example. Kurama needs time to realizes that Naruto is under a genjutsu and also time to dispell it. Several seconds will pass before he will be able to do that.
We saw it in the Sasuke vs. Bee fight. Sasuke used a weak version of Tsukuyomi and Hachibi needed about 4sec-7sec to break the genjutsu, Hachibi is the 2nd strongest Bijuu.
So if the second strongest Bijuu needs 4sec-7sec is it realistic that the strongest will need LESS than 1sec? Not really.
Even if yes, 0,1sec of Itachi´s Tsukuyomi still equals 7,2hours of torture, enough time to even kill someone like Naruto. Itachi went easy with Kakashi, he just stabbed him with a Katana (there are !WAY! more terrible ways of torture) and even let him rest (fade away) several times.
Only a skilled Uchiha has a chance to avoid his Tsukuyomi, or freaks like Kabuto who dont need to use their eyes
