Re: 24/192 Is very silly indeed
For a high end studio that has the resources to invest in the highest quality gear to be used by mix engineers, it is not silly.
For an artist making music without the resources of a large studio, there are probably wiser investments. Sample rates aren't the only field where audible quality is questionable for the price you pay vs. something else: Mic's, pre's, cables, other hardware, different software plugs that perform similiar functions, etc.
A technological feature isn't silly just because certain people can't hear differences: If an organization or individual has the money and chooses to invest in specific parts of their studio, it is worth it for them.
What I consider silly is saying recording at 24 bit is inferior to 16 bit: it increases headroom in a mix, which should be a desirable thing.