I entered MRR in my teens, as a hobby, and that was "nice for a young person to have a pastime". I took a 25 year holiday from it as life changes and came back into it a few years ago. My experience since:
Alot of the "stereotypical" lifetime modellers and even some hobby store staff look at my wife and I (DINKs) and seem puzzled by our fasination and our willingness to invest time and money.
My wife thinks its great...she's into early steam, I'm late diesel. We run her train as a tourist excursion while an AC6000 passes them by...it works for us. For good or bad, her plans for a layout are bigger than mine...
Our families are understanding...they have alot of their own time consuming niche hobbies. There is respect for each others hobbies...
Outside of that is a mixed lot...the reactions mentioned above, fascination, curiousity, and more often, keen interest, especially when we can show someone an AC6000 with DCC and sound doing its thing, or a 0-4-0 with lights and smoke running a loop. The toyish perception disappears...
I work in an office of 250 people, there are 3 MRR modellers, and about 5 interested, but can't find time/money. It seems to be a more popular hobby than knitting...