Why are the "laws" of physics so different as conceived by many xtian fundamentalist?

[robvalue]

I suppose it's a general discomfort with the idea that our understanding can only go so far.

It's healthy to ask, "But why does it work this way?". However, you also need to accept that the answer may be "We don't know", or that the truth of the matter might be that it just does. Insisting on a never ending chain of causation does not make it so. Of course, such a person must arbitrarily apply the latter to their god, to avoid it having to provide its own answer.