Actually Nun, you got it backwards. Before the bike boom, people tour with pretty light weight stuff on their 10 speed bikes. The lowest acceptable gear inches then was only 27". Yeah 27". Now, you need something like 16" or 20" GI or you don't have it low enough. Difference is the weight some people carry these days. I even see people tour cross country in the Rockies with 53 gears!
The so called touring bikes then were not made so heavy and so oversized tubings to resist the heavy loads of the rear panniers. I mean, some bikes sold in the early 80s were weighing not as much as a decent cyclocross bike now. Today, trucks like the LHT or the Raleigh Sojourn seemed to be a necessity. I was told that during the bike boom, this era attracted people from all walks of life to do bike touring and these people practically wanted to carry all the creatures comfort that you can camping and thus, people start carrying more stuff than they need to and bike companies make bikes to resolve issues like overweight panniers causing fish tailing by building heavier touring bikes. Just look at the average North American tourist heading to Mexico or Hawaii on a 1 or 2 week vacation with big 62" linear inches suitcases. I can do that with smaller than 18" carry on or even a small back pack.
Yes, the trend now is moving back to minimalist, just like the trend from aluminum bikes in the mid 90s back to steel now. It's not new, but it's a replay of the old.