Also, that feature you mentioned, while it works with some RCs (generally "source" or "input" key), doesn't take into account all the inputs which I am not using. So I need to go through a list of 4 or 5 devices including DVB-C cause yeah my monitor has that support even though I've never used that input. That's annoying.
It gets annoying the more often you gotta switch. For employees of government (like the mentioned example of the Pentagon) that's gonna be more often than not. Any downtime is then a waste because even if its merely 20 seconds back and forth it quickly adds up.
It could even make sense to have KVMs in businesses where they want to keep certain data strictly internal. But as long as companies aren't being punished for data leaks that doesn't have priority. Perhaps we'll eventually see a rise again of KVMs.
I think both of my current ones have built in (crappy) sound and both HDMI and Display-Port inputs.