But I like KuroKodzu and KenKuro. Let me explain. [BEWARE: SJW incomming]
I really, really like Kenma and I don't want to see him being the weaker person in the relationship. Kenma has spent years growing up under Kuro's wing, and in many ways he's dependent on Kuro. And that creates a power imbalance in the relationship.
When there's power imbalance, consent becomes an issue. It's really hard for the person with the lower social status to say no because there are consequences. They end up doing things they don't want, because they think they have to do it in order to avoid conflict. Kuro is much more confident and more skilled/experienced socially, plus he's older than Kenma. Kenma can be easily convinced and manipulated... and that's just not cool
It kills my suspension of disbelief when Kuro just does things to Kenma, because Kuro would never do that. He loves Kenma too much to potentially hurt Kenma, and he's too smart to doing anything that would ruin the good thing they have going on.
But it's a different story when they're both independent adults—Kenma finds his confidence and lives a life completely independently of Kuro. He's mature enough to be assertive and have things the way he wants. I can so imagine Kuro confessing when they're both grown up, and Kenma recognizing that there's no one in the world who will know him better, and there's no one who loves him as much as Kuro.
...and KenKuro is just cute ;D