I don't think it's sad at all. I think it's beautiful. Beyond the obvious fabulousness of the collection, I mean. They are quite old, and they've had a long, happy life together. They did what they wanted to do and had fun doing it. And they are still in love. That's way more than many people ever get in this life. This is a happy story.
As for the kid's corsets, you'll note that they are not "tight-laced" and tend to have a straight shape. Most corsets throughout history were meant to maintain posture and create a smooth silhouette, not to cinch the waist (and rearrange the guts, LOL). That sort of corseting was relatively short-lived (popular, for example, in the late Victorian era). The rest of the time, they were far less constricting. I doubt they were any more uncomfortable than, say, high heeled shoes or a wool swimsuit : ). When my civil war corset arrives, I'll let you know : ).