I was almost ready to agree with you until I looked at mine...
Most of my favorite forums have short names... until, of course, I scrolled down to "Home Repair & Improvement". That's the one forum name that seems the widest for me and that's the one that seems to set that column width.
It's not even that it's the long forum names, it's just that there is space on the left side of the column, just white!