We didn't use gates.
Gates are to protect against accidents, or to block off areas that children are not allowed in (like blocking off a room/ stairs/ etc.) imho, not to get...ahh...lazy is the wrong word (blocking off everything they *might* get into rather than teach boundaries, but I think you get my drift. But the point is: that's what playpens are for: to keep them away from schtuff (if you have a child who will use one). I suppose a whole collection of gates could create a giant playpen, but how do kids learn if they're kept in a bubble all the time? No one I know does that (although I know of some case studies). Everyone I know with gates also teaches boundaries. There's no way to teach boundaries without disciplining when they're crossed. Ranging from "Ah-Ah! Hot! No!" to "We don't play with the lamp/ door/ guillotine/ etc. If you touch it again you will go on timeout. Okay. Timeout."
My suspicion is that the people in your life saying you're wrong not to use gates are either ridiculously anal, or there's some kind of miscommunication.
That said... when you live in someone else's house in addition to your *own* rules, one often has to follow other peoples/ respect their boundaries. For example; when staying with my mum children are not allowed to clean. My OWN version of parenting in my own house, my son would help clean up every mess he made. In HER house, he did not. I preferred for the habit to set young + cause/effect. She preferred for the mess to be cleaned up quickly and completely (and small children don't do that). So when we were staying with her in her home, we followed her rules in regards to her home/ life/ her own boundaries.
If your family wants certain areas gated off so that the children don't get into that area (for whatever reason) that's a boundary that they're laying down along with the solution they can live with.
Now I'm just guessing as to the originator of the gate v boundaries quandry. If I'm wrong, no biggie, blow the person off and parent as you please. But if it's the family you're living with (or family/friends you're visiting, etc.) wanting certain areas gated off, they're totally within their rights to do so.