In other words, since what you call “pyramids” apparently are polysurfaces consisting of 4 triangular surfaces, they aren’t really what Rhino knows as “solids”. If you closed off the bottom of each of your pyramids with a square surface and joined all 5 surfaces you would have two solids which you could probably boolean successfully. I say probably because boolean ops are sensitive to intersections. Your “inner” solid would probably need to have it’s base very slightly outside the “outer” one.
Or, of course, you could start by simply adding the bases as above and doing the boolean on the bases to subtract the inner square from the outer one, then do the join to make the solid if that’s what you want to end up with.
If you want all 5 sides to have 1" walls, you’re out of luck. Rhino doesn’t know anything about that kind of object. If it’s really important to you to have something like that you can always pierce a small hole of some shape through one of the walls to connect the inner and outer surfaces. This will create a valid Rhino solid.