I do think the fault here is on the writers for not filling the audience in properly on what the hell motivates this guy.
People keep comparing DSC to the Battlestar Galactica reboot, but nuBSG understood that it was important to give the audience a full picture of their characters at the start so we would understand their behavior, even though they often did some pretty awful things. In general (and this is barring the stuff that the writers themselves hadn't figured out yet and revealed in later seasons), if the showrunners knew something about the characters or the world they inhabited, they put it up on screen as soon as possible. We were shown right off the bat that Bill Adama was lying about where Earth was, and we knew that Baltar was complicit in the destruction of the Colonies and was haunted by a fantasy of the Cylon woman he loved. We understood that Kara Thrace had a thing for Lee Adama and was responsible for the death of his brother due to her own feelings. We didn't have to guess at this stuff, it was all on screen from the start. And the fact that other characters didn't know the things we knew was an asset, because it could be mined for dramatic irony.
I worry that DSC is falling victim to the modern premium cable drama impulse to surprise us with big reveals, even if it comes at the cost of properly characterizing the cast. This "wait and see" attitude trades satisfying storytelling in the moment for the promise that there's some kind of payoff down the line, and it does so in service of the least durable storytelling mode: that of shocking this audience. It's not a trade-off I feel is worth it.