Oh I totally agree with this. When I place down a block on another block, it should not slide off of it on to the ground like it's greased and on ice during an earthquake.
It should stay put, at least until I hit it or walk on it. That part makes sense and I'm fine with it, but when I place a block, it should stay until something touches it.
Incredibly annoying when I'm trying to terraform and the land keeps randomly and imo illogically shifting around me while I'm placing blocks.