Because in here, the drama stems from longing to get close to another person, from feeling like the window you have to build a genuine connection is almost closed, from not knowing where one stands due to inexperience with navigating such a situation. There aren't love triangles or misunderstandings that could probably be solved within 10 seconds — just two men getting close and clumsily figuring out what they want from each other. It's not a complicated story, and sometimes keeping it simple is best.
The art is gorgeous; it is explicit, but the sex scenes are tastefully done and clearly show enjoyment (and with yaoi this bears mentioning: there is no non-consensual sex here). For me it's a great work; it could've been a bit longer, but that's just me wanting to see more of the couple and not a fault of the story (if anything, it's a plus).
The most I can argue is that the side characters don't really get development (or in some cases, names), but as this is Yoshino and Rou's story primarily, the others serve their purpose accordingly.
As for the enjoyment: well, I loved it so much that I jumped on MAL to write this pretty much as soon as I was done reading, so that should give you an idea.
