I think we have to accept the fact that morally grey characters do things that can never be justified. Not today, not a hundred years from now. But there's a difference between sympathy and empathy. Just because you don't support something, doesn't mean you also don't understand the character's motivations.
Bajaj in S1 did unquestionably debauched things. Things he can never take back and thing no one will justify. It's who he became AFTER THAT that really matters. The journey is what matters in good storytelling. I don't want characters who are white. Where's the fun in that? Where is the moral complexity in that?
As far as Komolika vs Bajaj is concerned, I think it's anyway far too soon to call a judgement. Her initial track is over, his haven't even properly began for us to sit here and play judge. Let's see it play out. But even if we have to go for surface level, Komolika was a half baked, one dimensional villain. She was also a narcissist and just plain stupid and didn't really evolve or have a character graph for people to hook onto. With Bajaj, it's different. Even if you put aside season assertions, Bajaj is intriguing because he's neither white nor completely black. He's shown sharp intellect, a backstory that you want to learn more about and his motivations are mostly in the dark for now. Which makes for excellent potential.
I can't justify the shit some of my most favorite characters do. And why should I? I would've probably dumped Game of Thrones on the first episode if that was the case. Journeys matter. The question that hooks you matters. And people following the journey of Bajaj right now are interested in watching his character go from point A to point B because there are so many possibilities. Everyone has a thing for something. Some people dig characters like Anurag. I find him flat for now. Who knows what the future holds.