While some might think mono-blue for control, the addition of black gives players access to creature removal like Soul Shatter and Professor Onyx
The unfortunate reality is that Mechtitan, despite its keyword soup textbox and enormous statline, has no built-in protection and is therefore just as susceptible to a Swords to Plowshares as any mere 1/1 would be
Thats way more than the fake mom, Giver of Runes, which only appears in 49,332 decks
I think the fact that Inquisition of Kozilek is more limited in scope this way definitely makes the card more interesting, but its universal enough that it helps alleviate Moderns historical issues around having too many narrow disruptions spells
There are two key differences here that you can rely on
It was competing against decks like UW Control using Consecrated Sphinx as its finisher