If you really want to know, SO many people complained about the small windows on the Phantom 820 and 630, that NZXT decided to go with a full panel window and no fan area. In fact, GPUs are quite a bit more efficient these days in terms of cooling, and so are cases. So, instead of carrying over the Fan mount from the original line, they made a full windowed panel.... and now people are complaining about a full windowed panel.
You need to look no further than my motto in my sig.
Sure they are. That's why my 780 throttles when it hit's a certain temperature... Stack it with one more (or two more) and the higher cards usually run 10c hotter than they would stand alone.
Then watercool, or buy a different case. Not every case is going to be tailor made for every person, especially in large-scale manufacturing. Many people gave their feedback about their desire to have a side window. There's 2 of you who want a side fan. I think NZXT, and every other good manufacturer out there, arre going to go with the feedback of the majority of their consumers.