This isn't a very hopeful quote given how many people continue to eat sausages even though we all know how sausages are made.
I'm doubtful. There's a few documentaries showing the process and I've had people tell me multiple times that they were genuinely shocked by it. I'm assuming those people "knew" and it's just that knowing "it's all the waste at the butcher getting stuffed into guts" is not quite the same as seeing it first hand.
Natural sausage casings are specialty items. If you're buying it at the grocery store, it's probably collagen (closely related to gelatin).
And it's not "all the waste". It includes fatty cuts that people wouldn't want to eat whole, but it doesn't include organ meats outside of specialty items.
Perhaps people find meat-grinding distressing, though it's really not all that different from ground beef. The emulsified filling of hot dogs and bologna looks odd, but the ingredients are inoffensive.
I'm less disturbed by sausage-making than by the slaughter and prime butchering of animals. They're no less dead and dismembered if you're eating a steak or pot roast. I'd rather we at least make use of all of the other parts.
Then again, some people find seeing a huge Industrial room full of raw meat distressing, perhaps somewhat analogously to how they might not be afraid of one spider but suddenly panick upon seeing hundreds at one spot.
Hunger is an unforgiving teacher, and the reality that our forebears grew expert at squeezing every last calorie out of everything in sight might afford a lesson.