Your 2 drop dealt 8 by the time the effect goes big. If the discard is getting cast, it was probably already over.
Unless you're concerned about the 2/1 flyer, which is sorta reasonable.
It's less
concern and more that I think there's more nuance to the gameplay experience when "creature that generates value" and "creature that meaningfully advances my game plan" are separate, on both sides of the table.
To put it a different way... Malcolm's a card that promises that it will do its
cool thing if you can attack with it 4+ times. Outside of proliferating, there isn't really a way to change this clock, and the upside of "going off" is so large that you'll always be a bit disappointed when villain kills it after you've put three chorus counters on it. And that's almost always going to happen, because, as you pointed out, the game's probably already over if villain can't stop Malcolm from going off.
In contrast, Shoreline Looter has a much narrower range between its normal functionality and its
cool thing (meaning that you're going to be less disappointed if villain kills it before you get there), it's less of an active threat if you don't buff it up (meaning that it's likely to live longer), and the countdown to drawing cards with it is based off of something that both players can manipulate through just playing the game.