Why don't you ever see them on touring bikes? I can see them being a bad idea from an aerodynamic perspective, but the comfortable riding position over a long tour makes more sense than leaning over all the time.
The handlebars that are being shown in the links are best known as North Road bars (with the exception of the Nitto Albatross). They were the typical 3-speed handlebars that are probably the most produced type in the world. Cruiser bars are very different, being generally wider and having a pronounced 'bow' shape. They are typically found on beach cruiser bikes with single speed/coaster brakes/balloon tires.
North Road bars are very ergonomic and can be extremely comfortable on very long rides, as long as you set them up right. I had a set on my Trek 520 for a long time. They take MTB brakes levers and bar-cons perfectly.
My tourer has north road bars, and with barend shifters they work really well for me - little or no handpain that I used to get with flat MTB bars or dropped bars. I do love them, combining them with a high stem. I feel just so...civilized.