[openbox] openbox philosophy on rounded corners (of windows)

[Globe Trotter]

Hello,

I have been looking around at different themes and one thing I have been missing in openbox is the inability to have rounded window corners. (Otherwise, this has been great, by and large!) I understand that this is a philosophical decision made by the developers? I wonder why? Is it because it can not be done in an easy way that also keeps resource usage low? I am looking at the following theme on box-look 

http://box-look.org/content/show.php/Ambiance+Crunchy?content=136162

which, turns out, though listed under openbox, is not necessarily an openbox theme. I guess, I am wondering what icewm and fluxbox give up, with their ability to have clean rounded corners on their windows. Ideally, I would have liked to combine this icewm theme:
http://box-look.org/content/show.php/IceBuntu?content=62935

with this openbox theme:
http://box-look.org/content/preview.php?preview=1&id=126725&file1=126725-1.jpg&file2=&file3=&name=Nodoka

(I like the rounded scrollbar here, very unique!)

Not wanting to start a war, but just wondering about the philosophy, and whether the reasoning is still relevant.....

Many thanks,
Trotter