If you've got children using your keyboard then a wireless one is a Godsend. Easier to get the various food crumbs out from between the keys. Just take it outside and brush it upsidedown with no need to unconnect. :-)
As I said, my ( who are now 15/17 ) have their own keyboards, but would have loved a 'removable' one when they were very little!And yes at that time would have placed keyboard on a very very high shelf.
Yes I could ... not use the supplied mouse ! But seems a waste.
As for wired /gaming , not for me.
So the question is still open , can you buy a wireless keyboard without a mouse ?
To be "eco friendly" none of us should use battery operated units if we can avoid. Sure you all will agree on that. Sometimes it's unavoidable, like me, I use a wireless keyboard because it's a big lump of plastic which I can't hide very well if tied to the comp. The mouse, on the other hand is easily hidden so it's ps2 connected. Having kids 26, 23, 16, 3 years old and one 14 months old I think I know a bit about parenting.
SG Atlantis®, glad to know that you are a diciplinarian, and your four year old listens to you.