I think this is a bit of a strawman argument. The "non-obvious" test isn't a test of the inventor's imagigination, but a test of the trviality of the inventive

I think this is a bit of a strawman argument. The "non-obvious" test isn't a test of the inventor's imagigination, but a test of the trviality of the inventive step. And it isn't a particularly high barrier to overcome in most cases. For example, one might invent a novel metal alloy, which would be patentable. However, "inventing" objects commonly made from metal (e.g. a knife) now to be made from this novel alloy would not be a creative step, and so not patentable.