Jordie,
I'm so hearing you... when I was pregnant I spent a small fortune on a cot set that came with bumpers, a doona and a pillow only to find I could not use any of them!!!
The walkers that don't walk- on Ebay they're called 'Exer-saucers'- are not recommended for the same leg problems as walkers.
No walker here but we have a jolly jumper. DS doesn't go in it for more than 20 minutes a day. I think common sense and moderation are the keys here- any equipment is going to cause damage if they spend all day in it!!
I think they go overboard for the same reason someone else mentioned- some people just don't think, so the powers that be spread the guilt and confusion to all of us to get the message through *sigh*