The surface of the moon is made of granulated rock a layer of loose regolith on top of a layer of steel-hard rock and compressed powder. The Lunar Modules tiny engine (9,900 lbs thrust) was powerful enough to blow the top layer of powder away, but nowhere near hot or energetic enough to gouge out a crater in the compacted regolith beneath it. Asking wheres the crater? underneath the Lunar Module makes as much sense as asking why a jet airliners engines (roughly 18,500-23,500 lbs thrust x 2 engines for a B727) dont blow a hole in a concrete runway every time one takes off. The answer is that neither vehicles engines produces anywhere near enough thrust to blast out a crater in a hard surface.
Without tin foil, why
would the internet exist?
(The crater "question"
still applies. Some pics
show moon dust at the landing,
footsteps by the LEM,
that kind of thing. So,
it wasn't blown away by
engines at landing.
Then why don't we see
a specific depression
in whatever's there?)