1) We KNOW there is at least two hostile Mangekyou Sharingan users out there: Itachi, and whoever the Trenchcoat MS user was that helped kill Sarutobi at the Exams. Obito may or may not be alive as well.I'm not saying strength contributes more then speed but that strength contributes something. If I understood the arguement it was that str doesn't contribute at all.
We also do main Iaido but apparently the mc switches styles after the first strike making str more relevant then what it would be if just Iaido was used.
Edit: I rather have a constant boost then a conditional trump card.
We know Danzo is still rocking Shisui's Mangekyou
We know Orochimaru can use Edo Tensei to summon inexhaustible zombies.
We know that Black Zetsu and his bodycontrol might be out there still.
When we need that conditional trump, we need it pretty badly.
2)Our Final Hurricane Seal is a conditional trump.
Dont knock them.