I am 42 and what I find great with Airbnbs is the place selection. There are so many of them even at places where hotels are rare, nonexistent or exorbitantly priced. Bellevue, WA and Florence, Italy are two places where I appear at least yearly and always Airbnb.
Plenty of cities are starting to introcude regulatory measures against airbnb which will make it much harder to stay profitable and grow. Munich, Berlin and Barcelona are all concerned that flats are often used only for airbnb nowadays, thereby removing them from the market, and have started measures to penalize flats used for airbnb (penalties up to 500 000 Euros). It's become a side business for a lot of rich people who buy flats explicitly for renting out via airbnb, not just temporarily renting out an unused room in your flat. I expect the backlash to become much stronger in the years to come.
I think "Airbnb" is entering our lexicon as a verb, the audience will widen. I hear the phrase "just airbnb your place" more than "just rent out your place". When people talk about travelling, they say "we'll just find an airbnb". "Airbnb" replacing hotel/rental/motel/bed and breakfast.
Likely lots of bias here as I'm a 30 something techie person, surrounded by like minded people.
I suspect this has as much to do with mass adoption as anything else. My wife runs four Airbnb units in Warren, Ohio and 2016 was a record year. We've been on Airbnb since 2013, but we really started seeing a change in the type and frequency of booking requests last year.
In the beginning, it was all 20-somethings traveling from big cities and staying a night or two. Last year, it was a much more diverse, more price-insensitive group.