I have a picture saved somewhere of using them up the wall in the playroom to protect for falls and protect walls from bumping. Haven't seen them in the kitchen. Not sure that is really an issue in most homes as we just keep on top of the kids and teach them how to behave properly - and that means not dumping their bowl of spaghetti on their head and then flinging wads against the walls. Have only had to wash walls of food once or twice and it was from juice being spilled and splattering - now all kids use lidded cups - problem solved.

I had some of the mats in my kitchen on the ceramic floor when our dog got older as she had trouble walking on the floor. I disliked how much actually collected between the seams on the floor under and had to take them up and sweep and wash often. In a playroom they would collect a lot less.

There was actually a post about the kind of foam used in the mats as containing something harmful but forget if that was just a scare tactic or if it was true. They are still sold and used so probably not something people worry about - again unless child uses them as a teething toy issue probably doesn't exist but worth looking up.

My basement playroom is carpeted and my main floor area is hardwood with an area carpet on it but no underpad - just the carpet meant to protect the floor not pad it whereas basement has a dense pad meant for potentially damp areas.