Simply to add several new sub-forums where suggestions can be placed in appropriate categories e.g. game play, forum enhancements, member conduct, whatever (or probably "miscellaneous")
Makes it easier to scan a sub-forum to see if an issue has been raised in an area for members to add comments one way or the other or to see that their thoughts have already been covered by others.
I also note that a lot of archived rejected suggestions have no reasons for the rejection or that they are so old that what can and can't be done is likely to have changed over the course of 3/4/5 years and could well be brought back into current discussions.