This has to be a troll thread, but I guess I'm going to bite.
The whole point of assassins is high risk, high reward. The silence never made sense on these champs because it made their trades and all-ins low risk, high reward. It gave them great laning potential with pretty much free trades because almost all of them could jump in, silence you, chunk you down, and retreat back to safety before the silence was over and you could trade back. It made their all-ins completely free because there was nothing you could do besides try to walk away from a champion with extremely high mobility that has roots or slows.
As far as Malz goes, hes a high risk champion all game. He has zero mobility and his ult has counters. He can't jump into your face while you're silenced and retreat back for free. Yes, he is very strong in a 1v1 scenario, that is true. But the truth is most people forget that Malz is also suppressed for the duration of his ult. In a team fight scenario, he is a squishy mage that is stuck in place for 2.5 seconds. He is as high risk of having his ult canceled by any form of hard CC and getting blown up. His entire kit is made completely useless by a
as well. Before you say it, yes I know it doesn't make sense for an AP mid to build a sash. But the likelyhood of Malz getting his ult off onto your AP mid in the back line is very low in a team fight. Even if the ADC and one other person on the team gets a QSS, Malz's options become super limited. He's either going to be forced to ult a tank or risk being an immobile mage trying to dive the back line. He doesnt have the same escape mechanics or safety of a Zed, Kass, or LB. This is Malz's trade off. This is his risk vs reward