Hmm, I have stairgates on my kitchen door, bottom of stairs, and ds's bedroom door. Because I don't want to constantly have to fetch him from upstairs, where he will be merrily squeezing toothpaste down the toilet, sprinkling talcum powder on the bed, strewing nappysacks across the landing, trying to run himself a bath, trying to hoover his bedroom, making "bouncyballs, mummy!" by throwing things down the stairs.
and in the kitchen, emptying the cupboards, feeding cat litter to the cat, putting potatoes in the dish washer, getting peas out of the freezer ("Look, little bouncyballs, mummy!"), loading the washing machine with Christmas tree decorations.
All of which he will do, if not either confined to the living room or his bedroom, or practically sat upon. I know he is three in April, but I also know my own child. If something is interesting to him, it doesn't matter how often he is told no, or timed out (not that I will do that just because he is curious), or removed from it, or distracted with an all singing, all dancing parent, he will return to it "as surely as a dog returneth to vomit".
If he cannot physically get to these temptations, I don't have to remove him, and he doesn't feel he has to have a tantrum. The stairgates are a stalling device now anyway, to give me time to get to him and head him off. He can open all of them given 2/3 minutes.
If it wasn't for the one on his bedroom door, I would never get a shower before work. If it wasn't for the one on the bottom of the stairs, I would never be able to cook. If it wasn't for the one on the kitchen door, I would never be able to sit on the sofa!
So, as you can guess, I feel quite strongly that some children may seem overprotected, but it is often because of the way the child was in the first place!