humm good place to start building a house a wall etc. better get the work bench out to help me build. how is this not a understandable concept ?

They are talking about the range of each of the benches. It's silly and sad that we need several if not hundreds to build anything worthy. Without the mods that override this dumb feature, you tend to get annoyed and go crazy building benches all over.

the workbench is tied to other mechanics like despawning items and preventing mob spawns.
it would be nice to tie those things to a small totem or something instead

I always find it interesting when posters make broad brush generalized statements holding them as truth when they are in fact, not.

"...every other game." I had to chuckle.

@Ccrack is on track as there are deeper game mechanics involved. And I find it nor overly difficult to place ( and then even remove once done building) a bench to build in a certain area.