From WW2 through the end of the 50s was an aberration in historical crime rates, and plenty of guns (and cash and liquor and...) were stolen from cars and trucks and houses forever. I like this chart of violent crime as it goes back so far, but similar rates for property crimes as well:
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Note also that it's dropped back down, and we're near recorded historical lows for violent and property crimes in the US. Even with slight upticks this year, they are relative, like the zigzags in the 1950-60 period there. Not a trend.
Hard to ask people valid questions about what they thought in the 1940s, or the 1890s (!) but smart people have said that aside from some possible political motivations to spread fear, we're more fearful because we have better communications. Facebook on down, even here, you hear of EVERY time anyone you even tangentially know gets in a violent alteracation, gets something stolen, or even just gets lightly scammed.
So, in the past: stuff got stolen a lot but it seemed more in isolation, so no one much noticed and either were just "it happens" replace and continue or maybe were a little more careful as they blamed themselves. Now, we blame "the very dangerous world" because our brains are wired to keep our families safe from jaguars hiding in the grass, and now there's a constant onslaught of reports of people eaten by jaguars, so we're paranoid.
And a little liability culture (which I tend to think we need
more of if we want to be considered responsible people).
As far as the OP, display: I know plenty who display other than the traditional locations, to keep the investment safe just for the future, theft aside. Over the fireplace dries out things, sunlight fades, for example. So, cabinets and the concept of the man cave so your stuff goes on hooks there even if not also an arms room so it's secure.
I know friends with glass fronted display cases, for some things still. I personally have no wall hangars, so all my guns are working and in the cage, but I have this in my office. People have seen it. No problems:
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Right click to open large if you want to zoom in.
Do I remember??? Mine is now a gnone cabinet. Got it in 1978. I remember when most hunters carried their long guns on a rack in the back window of the pick up truck without much worry of them being stolen. I'm 73. And I will tell you. People call this a sorry country, world or times. But it's not. It's the same country. The same world. And the time makes no difference. It's the people that makes the difference. And it's not the bad people. It's the "Good" people. The "Good" people that sit back and watch and say nothing. The scum can only come out if "You" let them. The gov. Can only go wrong if "You" let it. No, there's nothing wrong with the country, the world or the times. Just the "People".
One such incident he let an older boy hang it out the bus window and shot a rooster.....rest of us kids got off the bus to retrieve the prize and fight over the tail feathers. 
