I think you can have a gravel bike with only 35mm tires without being a poser.
I've been building up a "gravel" bike and mine will only have 35mm tires. I think the uses of my bike will be covered with 35's. I don't want to ride singletrack trails on any bike and definitely not my new gravel bike. I've got many miles of crushed limestone and smooth dirt road surfaces to explore.
Most of my bikes are old road bikes with 25mm tires and I really don't want to drag around wide tires during the warm season. In winter I ride a fatbike on snow and ice, so by spring I've had enough of wide slow tires.
If the 35's work for your planned uses, who cares how others look at your bike.